ALT 4 – Hedge Fund Strategies

Equity hedge fund strategies invest mainly in equity and equity-related instruments. The alpha comes from the sheer breadth of the global equity universe combined with skilful picking on both sides of the book. What usually determines how an equity hedge fund is classified is the size and the sign of its equity market exposure.

Four points on that spectrum matter. Long-only equity hedge funds hold long positions and sometimes use leverage. Long/short equity funds hold both long and short positions, which produces a more hedged and less volatile portfolio. Short-biased funds concentrate on strategic short selling of companies expected to lose value, occasionally with an activist inclination and occasionally with offsetting long positions. Equity market-neutral funds balance long and short exposures so that net exposure to the market, and to factors such as sector and size, is zero or close to it. They then look for pairs of securities whose relative prices have wandered away from their normal historical relationship, on the expectation that the relationship will reassert itself.

What the strategy actually does

Long/short equity managers buy the equities of companies they expect to rise, which means holding undervalued companies long, and sell short the equities of companies they expect to fall, which means holding overvalued companies short. The objective is flexibility: find attractive opportunities on either side and size them appropriately. Depending on the mandate, a manager can rotate between industry sectors, between factors such as value and growth, and between geographic regions. In practice most managers keep their philosophical biases and their areas of focus, and they lean heavily on fundamental research.

Market timing through beta tilts can contribute to performance, but the studies are not kind. Most fundamental long/short equity managers add little alpha through such adjustments, tending to be too net long at market highs and not net long enough at market lows. Stock selection therefore defines manager skill for most of them, with market timing an additive but secondary consideration. A manager who genuinely has timing skill is valuable from an allocation perspective precisely because the skill is rare. This is also the largest single strategy family in the industry, accounting for about 30% of all hedge funds.

Investment characteristics

Because skill comes mainly from stock selection, managers specialise, usually by geographic region, sector or investment style. Three characteristics define them: the strategy focus, the flexibility to hold long and short positions over time, and the use of leverage. Factor exposures follow directly from the mandate. A manager focused on small-cap growth stocks carries positive exposure to the size factor and negative exposure to the value factor. A manager focused on large-cap value carries the mirror image: negative size exposure and positive value exposure.

Equities drift upward over long horizons, so the typical book in this strategy carries a net long position. Some managers keep shorts on purely as protection against an unexpected downturn. Others are opportunistic and add shorts after uncovering problems with management, strategy or financial statements, or when valuation models flag selling opportunities in particular stocks or sectors. Performance during crisis periods is therefore an important differentiator between managers. Because fees are high, the goal must be idiosyncratic alpha, primarily from stock picking and secondarily from market timing, rather than embedded systematic beta that could be bought far more cheaply in a long-only fund.

Strategy implementation

When long and short positions are combined, what remains is the difference between the beta-adjusted long exposure and the beta-adjusted short exposure. A book with many strong sell ideas and a large short position can be net short for brief periods, but most managers settle at modest net long exposures averaging between 40% and 60% net long.

Many long/short equity managers are sector specialists, building the fund around their industry expertise and analysing situations they understand deeply, from the top down and from the bottom up at the same time. Natural areas of specialisation are the more complex sectors: telecom, media and technology, financials, consumer, health care and biotechnology, where sector knowledge adds real value. Generalists range more widely across industry groups and usually avoid the complex sectors. Biotechnology is the standard example, because corporate outcomes there can be binary depending on whether a drug trial succeeds. Generalists gain balance and flexibility but can miss industry subtleties that matter increasingly in a market where news arrives continuously and is heavily nuanced. In most cases the strategy ends up as a mix of alpha extracted from single-name selection on both sides plus some naturally net long embedded beta.

Dedicated short sellers hold short-only positions in equities they judge to be expensively priced against deteriorating fundamentals. They vary exposure only through portfolio sizing, at times by holding more cash. Short-biased managers run a less extreme version: they hunt the same expensive equities, but they may balance the short book with modest value-oriented or index-oriented long exposure, which helps them survive long bull markets.

Both types are trying to manufacture an uncorrelated or negatively correlated return stream. The raw material is the same in each case: a broken business model, accounting that turns out to be fraudulent, management that has lost control of the business, or any other development that will turn market opinion against a stock. The secular uptrend in global equities across recent decades has made this extremely hard, and there are fewer such managers today than in the 1990s. Volatility and economic disruption following the Covid-19 pandemic have widened the opportunity set again.

Activist short selling is a distinct practice: the manager takes a short position and then publishes the research behind the thesis. Where the manager has a solid reputation from earlier campaigns, publication tends to trigger a sharp price fall into which the activist can cover part of the position. In the United States, regulators have not treated this as market manipulation provided the activist does not publish erroneous information, does not charge for the research, which would create a conflict between subscribers and investors, and acts only in the interests of its limited partners.

Investment characteristics

Short sellers look for overvalued equities of companies whose fundamentals are deteriorating in ways the market has not yet perceived, and they aim to maximise returns during market declines. Where the approach works it supplies a genuinely negatively correlated return stream.

The mechanics are unforgiving. Short selling means borrowing securities, selling them high, then repurchasing them cheaply later and handing them back to whoever lent them. The manager must post collateral with the lender to cover potential losses, and must also service the securities loan with an interest payment that can become very expensive when the shares are hard to locate. A key risk is that the lender recalls the securities at an inopportune moment, before the expected decline has happened.

Risk management is also structurally harder than in long investing. A short position grows if prices advance against the seller and shrinks if prices decline, which is the opposite of the long-only case where losing positions naturally become smaller. Managers who become known as active short sellers can also find that company management stops taking their calls.

Regulation adds another layer. Many countries restrict short selling. The US alternative uptick rule works like this: once a share has dropped 10% or more against the previous close, any short sale must be filled above the highest standing bid, so the price has to be moving up before the order can go through. Many emerging markets have allowed short selling to enhance liquidity, and the Saudi Stock Exchange permitted short sales from 2016, but the risk of restriction in extreme conditions never disappears. During the global financial crisis the US SEC temporarily banned fresh short sales in a named group of financial shares, the stated purpose being to reduce systematic stress in the market.

Given the operational difficulty and the secular rise in equity markets, successful short sellers tend to strike quickly and then step back rather than holding a position indefinitely. The return profile of a good short-biased manager rises as the market falls and settles at roughly the risk-free rate when the market is going up. In an idealised world that would mean being short during down periods and holding low-risk government debt otherwise. The real objective is harder: pick short-sale stocks that still generate positive returns while the general trend is up. Targets are companies that are overvalued, that show revenues or earnings in decline, or that suffer from boardroom conflict, weak governance structures, or accounting that may prove fraudulent. Another category is companies whose future rests on a single product in development that the short seller believes will prove unsuccessful or non-repeatable.

Index construction is a genuine problem in this category. With so few short-selling managers in existence, assembling an index that is acceptably diverse is difficult. To take one example, only four managers sit inside the Lipper Dedicated Short-Bias Index.

Strategy implementation

Stock selection dominates the process. Managers work bottom up, scanning the universe of potential sell targets for the shares most likely to fall substantially over the relevant horizon, looking for inherently flawed business models, unsustainable corporate leverage, and signs of poor governance or accounting gimmickry. Useful screening tools include the spreads on single-name credit default swaps, the yield spreads on corporate bonds, and the implied volatility embedded in exchange-traded put options. Technical analysis and pattern recognition can help with the timing of the sale. Accounting measures also feature: the Altman Z-score gives a read on how close a company is to bankruptcy, and the Beneish M-score is designed to flag financial statements that may have been manipulated. Because the practice is so dangerous, most successful short sellers do substantial forensic work on each candidate, and in doing so they make the market as a whole more efficiently priced.

Equity market-neutral strategies, abbreviated EMN, take opposite positions in similar or related equities whose valuations have diverged, while holding net portfolio exposure to the market at or near zero. Managers neutralise market risk by constructing the portfolio so that expected portfolio beta is approximately zero. Many go further and set the betas for sectors and industries, and for common risk factors such as market size, the price to earnings ratio and the book to market ratio, equal to zero as well.

Because these portfolios take no beta risk and neutralise so many other factor risks, they normally have to apply leverage to both sides of the book to make the individual stock selections produce a meaningful expected return. Construction is often highly quantitative, holdings end up diverse, and positions are modified over relatively short horizons. Derivatives are an alternative route to the same place, with stock index futures and options used to drive the portfolio beta to zero. However the portfolio is built, the goal is the same: capture alpha while minimising beta exposure.

Four ways to build a market-neutral trade

Pairs trading is the most intuitive subset. A pair might be two similar companies where one looks cheap and the other expensive; it might be a holding company set against a subsidiary whose valuations have separated; or it might be two share classes of a single issuer, since multi-class stocks usually differ in voting rights. Whatever the pair, it becomes tradable when the prices fall out of alignment. Pairs are then monitored for their normal trading relationship, which conceptually is the degree of co-integration between the two price series. A position is established when unusually divergent spread pricing appears. The expectation is reversion to long-term mean values or to the fundamentally correct relationship, with the long leg rising and the short leg falling.

A caution attaches to purely quantitative pairs trading. Overall beta exposure is minimised, yet the book can still behave like a short volatility position when markets reach abnormal extremes of stress. That is less true where the trade rests on a fundamental pricing discrepancy that some identifiable event is expected to correct.

Stub trading pairs a parent company against its subsidiaries, with the weights set by how much of each subsidiary the parent owns. If parent company A owns 90% of subsidiary B and 75% of subsidiary C, and A looks expensive while B and C look cheap against their own historical mean valuations, the fund shorts one share of A and buys 0.90 shares of B together with 0.75 shares of C.

Multi-class trading works within a single issuer, trading one share class against another, most commonly voting against non-voting stock. The analysis mirrors pairs trading: establish how the returns of the two classes are co-integrated, examine the valuation metrics for each, and act when prices leave their normal ranges by shorting the expensive class and buying the cheap one. The gain comes from the relative pricing reverting to a more normal range.

Fundamental trade setups are not strictly equity market neutral but are still designed to be market neutral. A long or short equity position is hedged against an offsetting bond exposure where the relative pricing between the stock and the bond is out of alignment. This is capital structure arbitrage, and it is discussed again under event-driven strategies. Attractive expected outcomes here usually come from relative mispricings that exploit a potential event, such as a merger or a bankruptcy, that would change relative pricing. A market-neutral strategy can equally be built by positioning two bonds against each other, for instance to exploit a misunderstood difference in covenants or a differential asset recovery.

Quantitative market neutral and statistical arbitrage

When large numbers of securities are traded and positions are adjusted daily or hourly using algorithmic models, the manager is described as a quantitative market-neutral manager. The frequency is driven by the fact that market prices move faster than company fundamentals, and each move triggers a rebalancing back to neutrality. When the horizon shrinks further and the emphasis falls on mean reversion and relative momentum in market behaviour, the practice becomes statistical arbitrage trading.

There is a permanent tension here between holding a perfectly beta-neutral portfolio and paying the market impact and brokerage costs of near-continuous adjustment. Many EMN managers run trading-cost hurdle models to decide whether a rebalance is worth executing at all. Security selection remains the main source of skill, with market timing secondary. Sector exposure is usually constrained, although this varies by manager. A manager who is beta neutral overall but generates alpha by rotating between sectors goes by a different name: a market-neutral tactical asset allocator, or a macro-oriented market-neutral manager.

Investment characteristics

EMN managers insulate the portfolio from overall market movements and take advantage of divergent valuations in specific securities. The process is often quantitative and uses substantial leverage to make the return objective meaningful, although many discretionary EMN managers use significantly less.

These funds are most useful for allocation during non-trending or declining markets, because their returns are steadier and less volatile than most other hedge strategies. The conservative and constrained approach normally delivers less volatile returns than a manager who accepts beta exposure. The exception is when significant leverage forces portfolio downsizing. Prime brokers offer portfolio margining, and under it a market-neutral book can be run as far as 300% long against 300% short. Those margining rules hold only until losses reach a defined threshold, described as an excess drawdown, after which the broker can compel the manager to cut overall exposure. That is a key strategy risk, and it bites hardest on the quantitative managers.

Despite the leverage, the steady risk and return profile means EMN managers are often treated as preferred replacements for, or at least complements to, a fixed-income allocation at times when bond returns look unattractively low or the curve has flattened. The alpha is of a completely different kind, with completely different risks. EMN managers face leverage risk, which includes both the availability and the cost of leverage, and tail risk, which is the behaviour of a levered portfolio during market stress.

Strategy implementation in four steps

1. Evaluate the investment universe, keeping only securities that trade freely, carry enough liquidity, and can realistically be borrowed for shorting.
2. Screen for buy and sell candidates, using fundamental models that take company, industry and economic data as valuation inputs alongside statistical or momentum-based models.
3. Construct the portfolio under constraints that maintain market risk neutrality, so that the market value-weighted beta is approximately zero, often with money, sector or other factor neutrality imposed as well.
4. Consider the availability and cost of leverage against the desired return profile and the acceptable drawdown risk, and introduce rebalancing execution costs as a filter on how often the portfolio should be rebalanced.

Markets are dynamic because volatility and leverage change constantly, so exposure to the market is always drifting. EMN managers must actively manage exposures to stay neutral over time, yet every rebalance costs money. The discipline is to avoid letting those costs overwhelm the security-selection alpha the strategy is designed to capture.

A caveat on that example. It is deliberately simplified. In reality most EMN managers would not hedge beta stock by stock but would hedge beta at the level of the overall portfolio, and they would also take account of other security factor attributes.

Event-driven managers hold corporate securities and derivatives with a view to profiting from how a specific corporate event resolves. The event list is long: a merger or acquisition, a bankruptcy, a share issuance or buyback, a capital restructuring, a reorganisation, an accounting change. The analytical work runs through financial statements and regulatory filings, examines corporate governance closely, covering management structure, board composition, matters put to shareholders and proxy voting, and assesses strategic objectives and competitive position.

There are two ways to time an event-driven position. A soft-catalyst approach commits capital ahead of an event, before it has happened at all. A hard-catalyst approach waits for the announcement and then invests where prices have not yet converged fully. Waiting for the hard catalyst produces a less volatile and less risky book. Merger arbitrage and distressed securities are the most common event-driven strategies.

The two deal structures

Mergers and acquisitions are classified by method of purchase. In a cash-for-stock acquisition the acquirer A offers the target T a cash price per share. If T trades at $30 and A offers $40 per share, A is offering a 33% premium, because $40 ÷ $30 − 1 = 0.333. A stock-for-stock acquisition instead exchanges a stated number of acquirer shares for each target share. With A at $20 and an offer of 2 acquirer shares for each T share, the holder of a T share ends up with $40 of value, provided the A price holds until completion.

Deal structures vary for tax reasons, for reasons of corporate structure, or because a defence has been built in to discourage a bid. The poison pill is the standard example. It is a pre-offer defence under which the bondholders of the target may put their bonds back to the company at a redemption price fixed in advance, usually at par or better, so the bidder must find more cash and the acquisition becomes more expensive. As a general pattern, acquirers offer cash when cash surpluses are high, and use stock when share prices are high and management regards its own shares as richly valued, treating overvalued shares as a currency.

Investment characteristics

In a cash-for-stock deal the manager may simply buy the target, expecting it to rise towards the offer price on completion. In a stock-for-stock deal the usual construction is long T against short A, sized on the exchange ratio itself, with the spread as the prize once the deal closes. If the deal fails, the manager loses on both legs, because the price of T has already risen and the price of A has already fallen in anticipation. Less often a manager takes the opposite view, that the deal will fail, usually because of anti-competition or other regulatory concerns, and then sells T and buys A.

On announcement, the target price generally rises towards the acquisition price and the acquirer price falls, either because of potential dilution of its shares or because cash is being used for something other than a dividend. The lag between announcement and closing means a deal can always fail: financing may not materialise, regulators may object, or financial due diligence may not pass. Hostile bids, where target management has not agreed the terms, are less likely to complete than friendly takeovers where management has already agreed.

Somewhere between 70% and 90% of mergers announced in the US market eventually complete. Allowing for the failures, for the costs of establishing the position such as borrowing the acquirer stock and commissions, and for the risk that terms are renegotiated in stressed markets, merger arbitrage typically offers a 3% to 7% return spread depending on deal-specific risks, with a particularly risky deal carrying more. If the average deal takes 3 to 4 months, the same capital can be turned over into fresh deals more than once a year, and modest leverage lifts net annualised returns into the 7% to 12% range, with returns driven by deal outcomes rather than by market factors. Spreading capital across many mergers, deal types and industries hedges the risk that any single one collapses.

The left tail is the thing to respect. When deals fail, the initial rise in the target and fall in the acquirer typically reverse. Arbitrageurs who entered after the announcement can lose heavily on the long target and short acquirer positions, often as much as negative 20% to 40%.

The payoff is a bond plus a short put

Corporate events are binary: an acquisition either succeeds or fails. That makes merger arbitrage economically equivalent to selling insurance on the deal. If it succeeds, no adverse event occurs and the manager collects the spread, exactly as an insurer collects a premium for bearing event risk. If it fails, the manager pays out on both legs, as an insurer pays a policy benefit. The payoff profile therefore resembles a riskless bond plus a short put option. The arbitrageur also holds something extra: a call option that becomes valuable if a White Knight, meaning another interested acquirer, bids higher for the target before the original proposal completes.

Strategy implementation

Positions are usually established in common equities, but the toolkit extends across the capital structure and into derivatives: junior and senior debt, preferred stock, convertibles and options are all used for positioning and for hedging. In a cash-for-stock deal the manager may use leverage to buy the target. In a stock-for-stock deal leverage is also common, but shorting the acquirer can be difficult because of liquidity or short-selling constraints, which is a particular problem in emerging markets.

Derivatives solve several of these problems. Out-of-the-money puts on the target, and out-of-the-money calls on the acquirer to cover the short, are the two standard overlays. Convertible securities give asymmetric payoffs: the convertible bonds of the target rise as the target shares rise on the acquisition, while their bond value cushions the fall if the deal fails. Where the acquirer credit is superior to the target credit, credit default swaps can be used. Protection is sold on the target, meaning the CDS is shorted, to benefit from its improving credit quality and the fall in the price of protection once the merger completes. If protection is cheap enough, buying it on the target instead can act as a partial hedge against deal failure. Broad market risk that might disrupt completion can be hedged with short equity index ETFs or futures, or with long index put positions.

The true source of alpha, however, is not the implementation. It sits in the first judgement of all: which deals to take on, and which to leave alone. Once in a deal, there are many ways to express the position depending on the deal-specific view.

Distressed securities strategies target companies already inside bankruptcy, heading towards it, or merely under financial stress. The routes into that condition are familiar: a business that has lost its edge, a balance sheet carrying too much debt, governance that has broken down, accounting irregularities, or fraud. Their securities have usually been cleared out of long-only portfolios by then, and can trade far below what they would be worth once the business is properly run again.

Hedge funds are natural buyers here for two structural reasons. They are not bound by institutional requirements on minimum credit quality, and they offer their own investors only periodic liquidity, typically quarterly and sometimes annually, which makes illiquid holdings far less problematic than they would be inside a mutual fund. Mispriced securities can be picked up ahead of a bankruptcy filing, in the middle of the proceedings, or after they conclude, and hedge funds generally aim to realise returns faster than a private equity firm would. That is not universal: managers in some distressed sovereign debt, in places such as Sri Lanka or Venezuela, face very long horizons before collecting.

Some distressed managers set out to control an entire class of securities within the capital structure, because that gives them creditor control over the bankruptcy or the reorganisation. Which class provides that control varies by country and by bankruptcy law. Active managers build concentrated positions and take board seats at the companies they are trying to turn around. Passive managers leave others to fund the legal bills of a capital structure reorganisation, which are often substantial and can include expensive proxy contests.

Distressed debt and other illiquid assets can take years to resolve and are hard to value, so managers running these portfolios require long initial lock-up periods, for example no redemptions for the first two years. Gates may also be set at the level of the fund or of the individual investor, capping what can be withdrawn in any one quarter. On valuation, external specialists may be needed to give an independent estimate of fair value. Where a security has little or no liquidity, and is classified as a Level 3 asset under the relevant accounting standards, its price is derived from a model, and that process smooths reported returns.

Liquidation against reorganisation

Bankruptcy typically produces one of two outcomes.

• Liquidation. The assets are sold off over some period and holders are paid sequentially by priority of claim: senior secured debt, then junior secured debt, then unsecured debt, then convertible debt, then preferred stock, and finally common stock.
• Reorganisation. The capital structure is rebuilt and the terms attached to existing claims are renegotiated. Holders of debt may agree to a longer maturity, or may swap their claims for shares in the restructured business. Existing equity is cancelled, leaving existing shareholders with nothing, and new equity is issued and sold to new investors to raise funds and improve the financial condition of the firm.

Investment characteristics

Many institutional investors, banks and insurance companies among them, cannot hold non-investment-grade securities under their mandates and must therefore sell as a company deteriorates. Forced selling of that kind dries up liquidity and forces heavy discounts into whatever trades do print, and that is where the opportunity comes from. The path from financial distress to bankruptcy can also unfold over long periods, and the complexity of the legal proceedings creates informational inefficiencies that leave securities improperly valued.

Doing this well needs specific skills: reading complicated legal proceedings, understanding bankruptcy processes and creditor committee discussions, modelling reorganisation scenarios, and anticipating how the market will react to each of them. Depending on relative pricing, managers may build capital structure arbitrage positions in the same distressed entity, going long the securities where recovery looks acceptable and short other securities, including the equity, where recovery prospects are poor.

Market conditions matter throughout. A liquidation that has to move fast will realise discounted prices and a lower total recovery rate. Once illiquid assets have to be shifted in a hurry, forced selling and liquidity spirals push prices down to fire-sale levels. In a reorganisation, current market conditions partly determine whether the firm can raise capital from asset sales or from issuing new equity, and how much.

Alpha in distressed securities tends to be idiosyncratic. The strategy capitalises on information inefficiencies and on the structural inability of traditional managers to hold such securities at all.

Strategy implementation

In a liquidation, the work is estimating the recovery value for each class of claimant. If the manager estimate of recovery exceeds market expectations, perhaps because of illiquidity, the manager buys the undervalued debt and expects to realise the higher recovery rate. Suppose the senior secured debt of bankrupt company X is priced at 50% of par. By researching the quality of the collateral and estimating the potential cash flows in liquidation and their timing, the manager estimates a recovery rate of 75% and buys the debt expecting to capture the difference. Timing the legal process matters as much as valuing the claim, and specialist bankruptcy counsel is normally needed to judge it, because proceedings can run for several years. Even a correct recovery estimate may be only partly realised, or not realised at all, if the process drags on or market conditions deteriorate.

In a reorganisation, the questions are how the finances will be rebuilt, what the operating business is worth, and what each class of claim will eventually be worth. The manager evaluates the securities of the company and buys those that look undervalued given the likely outcome. The choice of security also depends on whether the manager wants a control position. If so, the manager will be active in negotiations and will seek to identify fulcrum securities. These are claims that sit partially in the money, will not be paid in full, and whose owners finish up holding the equity of the restructured company. Where too much debt rather than a broken business caused the trouble, the restructuring may convert the senior unsecured debt the manager bought into new shares, cancelling existing debt and equity, while new equity investors inject fresh capital. As the distress recedes and the restructured company is worth more, a flotation normally follows. The manager sells into it, and the profit is the gap between the price paid for the cheap senior unsecured debt and the proceeds of the new shares.

Equity market neutral is itself one equity-oriented form of relative value investing. The other common forms involve fixed-income securities and hybrid convertible debt, and like equity market neutral they use leverage heavily. Relative valuations move apart for three reasons: credit quality shifts, liquidity shifts, and, where an option is embedded in the security, implied volatility shifts. Under ordinary conditions the strategies collect a premium for bearing credit, liquidity or volatility risk. When a crisis arrives and leverage, credit deterioration, illiquidity and a volatility spike all land at once, the same strategies lose money.

Fixed-income arbitrage hunts mispricings by pairing long and short positions among debt instruments of every kind: government and corporate bonds, bank loans, and consumer paper such as student loans, credit card receivables and mortgage-backed securities. Opportunities arise wherever two instruments differ in duration, in credit quality, in liquidity or in embedded optionality.

Investment characteristics

In its simplest form the strategy buys the relatively undervalued security and sells short the relatively overvalued one, expecting the mispricing to resolve itself within the investment horizon. Four things push valuations outside their normal historical ranges: a difference in credit quality, meaning investment grade against non-investment grade; a difference in liquidity, meaning on-the-run against off-the-run; a difference in expected volatility, which matters most where an option is embedded; and even a difference in issue size. Stated more generally, the manager is trading today’s prices against where the relationship between them is expected to settle, and reversion to the mean is one important part of that. Positive net carry is frequently a goal in its own right, and capturing it may mean trading a kink in the curve or positioning for the curve to change shape.

Where the positioning involves accepting relative credit risks across different issuers, fixed-income arbitrage becomes what is more broadly called long/short credit trading. That version is naturally more volatile than exploiting small pricing differences within sovereign debt alone.

Unless the price discrepancy itself requires a yield curve exposure, arbitrageurs neutralise the duration of the two legs so that interest rate risk drops out. Duration neutrality only hedges small shifts in the curve. Larger yield moves, and non-parallel moves such as a steepening or a flattening, require derivatives: futures, forwards, swaps, and swaptions, which are simply options on a swap. Complexity varies by instrument. Plain government debt adds sovereign risk, and sometimes currency risk, to its interest rate risk, and neither is trivial in many countries, while securitised paper backed by assets or mortgages brings credit risk and pre-payment risk instead. Derivatives help hedge those too.

Pricing inefficiencies in fixed income are usually very small, particularly in developed markets, but the correlation across different securities is typically very high. That combination makes substantial leverage both necessary and acceptable. A ratio of 4 to 5 times assets to equity is typical. Inside some market-neutral multi-strategy funds, where fixed-income arbitrage is only a portion of total risk, the sleeve can be run at 12 to 15 times assets to equity. Leverage magnifies every risk the strategy carries, especially in stressed conditions.

A further complication is the enthusiasm of financial engineers for tranching structured products around fixed-income cash flows, residential mortgages above all, in order to separate out particular credit and prepayment risks. Inside a mortgage pool the cash flows may be sliced so that one set of credit tranche holders ranks ahead of another, or so that the interest payments and the principal payments flow to different owners. Relative value strategies built on that collateral carry a particular set of risks that only show up under stress: the negative convexity of many mortgage-backed securities and of the structures wrapped around them, default rates running ahead of assumptions once volatility rises, the balance sheet leverage of the funds themselves, and redemption pressure from their own investors.

Finally, scale and opacity. Measured by issuance, global debt markets dwarf equity markets, and the instrument types run into the thousands. Outside on-the-run government paper and other sovereign-backed issues, which trade freely in developed markets, liquidity is generally poor. Prices are naturally opaque and have to be worked out, which is hardest for off-the-run paper that trades only now and then, and depth in parts of the municipal and corporate markets can be very thin indeed. That is where the opportunity lives, and it is also where the positioning and liquidity risk lives.

More granular relative value indexes also exist within the same families, split by sovereign bonds trading, by credit trading and by asset-backed trading.

Strategy implementation

Yield curve trades. The workhorse is the calendar spread, which takes offsetting positions at two points on the curve where the relative mispricing is largest, for instance ahead of a flattening or a steepening. Macroeconomic forecasts form the backdrop. Both legs may come from a single issuer, in which case credit and liquidity risk largely cancel and interest rate risk is what remains, or from two issuers, normally operating in one industry, in which case credit quality, liquidity, volatility and issue-specific features are what drive the gap. Either way the manager profits as mean reversion occurs, with the longs rising and the shorts falling inside the target time frame.

Carry trades. Here the manager owns the higher yielding instrument and is short the lower yielding one, collecting positive carry while waiting for the temporary mispricing to close on both legs. The textbook version is long an illiquid off-the-run government bond against a short in the liquid on-the-run issue of matched duration. Duration and credit exposure are identical on both sides, so those risks wash out and liquidity risk is what the manager is really being paid for. In normal times the expensive on-the-run bond cheapens and the off-the-run bond richens, because a fresh auction produces a new on-the-run issue and pushes the old one into the off-the-run category.

The payoff profile of this carry trade resembles a short put option. When it works, the manager keeps the carry and adds a gain as the spread closes. When the spread widens instead, the payoff turns negative. Because mispricing of government securities is generally small, substantial leverage is applied, and once positions are that levered, even a brief adverse price move can set off margin calls that force liquidation at heavy losses. Curve trades, carry trades and relative credit trades are only the entry points, and the strategies built on top of them can be far more intricate.

Convertible bonds are hybrid securities. The cleanest way to see one is as a plain bond bundled with a purchased call on the equity, where the exercise price is the strike multiplied by the conversion ratio. Three definitions do most of the work:

• The conversion ratio tells you how many shares one bond converts into.
• The conversion value is that ratio multiplied by the prevailing share price.
• The conversion price is the prevailing bond price divided by the same ratio.

Where conversion value sits well under the price of the bond, which is the same statement as the share price sitting well under the conversion price, the option is out of the money and the security trades like ordinary debt. Where conversion value sits well above the bond price, the option is in the money and the security starts tracking the shares.

Investment characteristics

Convertibles are complex and generally not well understood. Several inputs move their prices at once: the level of interest rates, the credit spread of the issuer, the coupon and redemption cash flows of the bond itself, and the value of the embedded option, which in turn depends on dividends, on the path of the share price and on how volatile the equity is. Issuance is sporadic and small relative to straight debt, which leaves most of these bonds thinly traded. Most are non-rated and carry fewer covenants than straight bonds.

That combination produces the structural opportunity. Because the equity option is buried inside a complex security that rarely trades, its implied volatility tends to be marked well below the volatility the underlying share actually realises. Supply drives the cycle too: the heavier the new issuance the market has to digest, the cheaper the paper gets and the better the arbitrage looks.

The central problem for the arbitrageur is that reaching the cheap embedded optionality means accepting or hedging away everything else in the security: interest rate risk, the credit risk of the issuer, and market risk, meaning the risk that the stock price falls and renders the embedded call less valuable. Each of these has a hedge available. Rates can be hedged with interest rate derivatives, issuer credit with a default swap, and equity exposure by shorting a delta-adjusted quantity of the shares, or by buying puts instead of selling stock. Every hedging tool used, however, erodes some of the attractiveness of the position it is protecting.

Managers therefore differentiate themselves by which risks they choose to leave open. Credit-oriented convertible managers decline to hedge the credit default risk of the issuer and take the position partly as a credit view. Others hedge the credit risk but take a long-biased directional view of the stock and deliberately underhedge the equity exposure. Volatility-oriented convertible managers go the other way, selling more stock than delta requires so the book leans bearish on the shares, which sharpens the exposure to a rise in volatility.

This is one of the core strategy areas in the industry, and multi-strategy houses commonly run it in the same building as their long/short equity, merger arbitrage and distressed books.

Strategy implementation

The classic trade buys the cheap convertible and sells the expensive shares against it. How many shares to short in order to sit delta neutral is set by the delta of the convertible itself. When the conversion price is low against the current share price, so the embedded call sits deep in the money, delta approaches 1. When the conversion price is high against the share price, so the call is out of the money, delta approaches 0.

Combining a long convertible with a short equity delta exposure leaves the portfolio essentially balanced for small changes in the equity price. As the stock moves further, the delta hedge changes, because the convertible carries the natural positive convexity of positive gamma while stock gamma is always zero. The consequence is that the arbitrageur drifts synthetically longer in equity as the share rises, and synthetically shorter as it falls. That drift is then hedged at favourable prices by resizing the short: more stock sold as prices rise, stock bought back as prices fall. Large enough swings in the share price, together with disciplined rebalancing and everything else held equal, make the strategy profitable. Put precisely: the arbitrageur gains whenever the volatility the equity actually realises exceeds the implied volatility paid for inside the convertible, after hedging costs.

Three circumstances create trouble.

1. The borrow. Shares must be located and borrowed, and the owner may want them back at an inopportune moment, such as during a price run-up or whenever supply is low and demand is high. A short squeeze can produce substantial losses and a suddenly unbalanced exposure. Fixing the borrow for a defined term reduces the danger and adds to the cost.
2. Credit. The bond carries issuer credit risk, so any move in spreads, in either direction, throws the value of the convertible out of line with the value of the equity hedge, and the manager may or may not have hedged that separately.
3. Time decay. The embedded call decays, and that decay costs money whenever realised equity volatility falls away or implied volatility compresses across the market as a whole.

Extreme market volatility is not the friend of this strategy that it might appear to be. Extreme volatility usually implies heightened credit risk, and because convertibles are naturally less liquid, convertible managers generally do not fare well in such periods. Worse, hedge funds are now the effective market makers in convertibles, and a crisis is exactly when their own investors ask for money back, which sharpens the left-tail risk in the strategy just when it hurts most.

Opportunistic managers hunt returns anywhere they can find them, across many markets, many instruments and many techniques. Their unit of analysis is not the individual security but the asset class, the sector, the region, the macro theme and the relationship between one asset class and another, worldwide. Returns are consequently driven by big themes, by global linkages, and by where markets sit in a trend or a cycle.

These funds resist neat categorisation, but they can generally be divided on three dimensions: the type of analysis driving the strategy, which is technical or fundamental; how decisions are implemented, which is discretionary or systematic; and the instruments and markets traded.

• Fundamental strategies take economic data as their raw input and concentrate on what a security, a sector, a market or a relationship between markets ought to be worth.
• Technical analysis uses statistical methods to predict relative price movements from past price trends.
• Discretionary implementation relies on manager skill to interpret new information and make decisions, and it can be subject to behavioural biases such as overconfidence and loss aversion.
• Systematic implementation follows fixed rules, coded into algorithms that trade with minimal human involvement, but it can struggle with new and complex situations that have no historical precedent.

Scale has created a new problem for the systematic side. As systematic trend-following funds have grown, so has negative execution slippage caused by multiple trend-following models reversing at once, producing a herding effect. That can temporarily overwhelm normal market liquidity and distort fundamental pricing, giving the trend-following overshoots that momentum-signal triggers create.

What global macro managers do

Global macro managers trade relationships between markets worldwide, across almost every instrument available. The derivative toolkit alone spans futures, forwards, swaps and options written on metals both precious and base, on other commodities, on currencies, and on bond and equity indexes. Cash instruments sit alongside them: government paper, corporate credit and single stocks. Because the possibilities are so wide, managers tend to concentrate on themes, for example trading undervalued emerging market currencies against an overvalued US dollar using OTC currency swaps; on regions, for example trading stock index futures on the Italian FTSE MIB against the German DAX to capture differences in eurozone equity valuations; or on styles, for example systematic against discretionary spread trading in energy futures. The views behind these trades concern how healthy each economy is, what its central bank is likely to do, how the yield curves relate to one another, where inflation and relative purchasing power are heading, and how capital and trade flows are moving. Most of that gets expressed as a currency position or a position on a rate curve.

Macro managers are anticipatory and sometimes contrarian. Some try to extract carry gains or ride momentum, but most tend to be early and then benefit when rationality returns to relative pricing. That makes an allocation to global macro particularly useful when a sudden reversal in markets is feared. The canonical illustration is the subprime mortgage crisis. A number of these managers saw the American housing problem forming as early as 2006 and bought credit default swap protection, sometimes on the mortgage bonds themselves, sometimes on tranches of the structures built from them, and sometimes just on whichever broad credit index looked most exposed. They had to wait until 2007 and 2008 for those positions to pay off, but some performed spectacularly as conditions turned into the global financial crisis, and holding such a manager inside a larger portfolio proved very valuable.

One caution: because global macro managers trade a wide variety of instruments and markets by different methods, they are a heterogeneous group. They are therefore not as consistently dependable a source of short alpha as pure systematic trend-following managed futures funds, which attempt to capture any significant market trend. Their compensating advantage is that they are more anticipatory.

Investment characteristics

Global macro managers draw on fundamental and technical analysis alike when valuing a market, and they implement both discretionarily and systematically. The view taken can be directional, for example buying the bonds of banks expected to benefit from a normalisation of US interest rates, or thematic, for example buying the winners and shorting the losers from Brexit. Because of the heterogeneity, an allocator needs extra due diligence and close attention to the current portfolio in order to anticipate correctly what factor risks a given manager will deliver.

Leverage is a common feature, usually obtained through derivatives. Posting 15% to 25% of equity as margin against futures or forward positions gives control of a face amount running to 6 or 7 times the assets of the fund. That embedded leverage gives the manager ease and flexibility in both relative value and directional positioning.

Returns come from spotting a trend in a global market and being positioned for it, which is why a quiet, mean-reverting market is the natural enemy of the strategy. Sharp falls in equities, a change of regime in interest rates, a currency devaluation, a jump in volatility, or a geopolitical shock from a trade war or an act of terrorism are the risks the strategy carries and, at the same time, the events it exists to exploit. Positions may fail to react as expected because of unforeseen contrary factors or because the anticipated global risk simply does not materialise. Macro managers therefore produce lumpier and more uneven return streams than most other hedge fund strategies, with generally higher volatility.

The environment matters enormously. Quantitative easing after the global financial crisis kept conditions benign for most of the following decade, and benign conditions are close to the worst possible setting for this strategy. Equity and fixed-income markets trended higher, but volatility across those and many other markets, including currencies and commodities, was relatively low, and in some cases central bankers intervened to curtail undesirable outcomes and thereby prevented macro trends from fully forming. Because intervention moderates both the trendiness and the volatility that are the lifeblood of the strategy, some allocators began avoiding it altogether. That may be shortsighted, since opportunistic strategies can be very useful across a full market cycle for diversification and alpha, and the sharp reversal of monetary policy after the Covid-19 pandemic demonstrated the opportunity set returning.

Strategy implementation

The process runs from the top down, using macroeconomic and fundamental models to form a view on where an asset or an asset class is heading, or on what it is worth relative to something else. The instruments used to express it can be anything: single securities, baskets, index futures, currency futures and forwards, metals contracts, agricultural contracts, cash bonds or bond futures, and options written on any of the above.

A directional bet is driven by fundamental data on one market or asset, judged against its own history and against the macro trend expected ahead, to decide whether it is cheap or expensive. Relative value positioning asks a different question: which of two assets is cheap against the other, given historical and expected macro conditions. Take the ASEAN block countries, meaning Indonesia, Malaysia, the Philippines, Singapore and Thailand. Suppose their currencies are weakening against the dollar. A directional model may read that as making the shares of the big exporters cheap, and recommend buying them. Dig further and the public bonds of those same exporters may look cheaper still against the shares, in which case the trade becomes long the bonds and short the equity. Such a gap is likely for a simple reason: equity prices absorb a currency move almost immediately, while bond prices take longer to catch up.

Success needs two things at once: a correct fundamental view of the market, and the proper method and timing to express it tactically. Managers who repeatedly enter too early, exit too late, or choose an inappropriate implementation will face redemptions. Given the natural leverage available, managers can be tempted to carry too many positions at once, but the diversification benefit of doing so is typically smaller than in more idiosyncratic long/short equity strategies. The reason is the nature of risk-on and risk-off conditions, often driven by central bank policy, which move a variety of asset classes in a correlated way.

The academic case for managed futures was first made by John Lintner, in a 1983 paper that is still cited. The strategy trades futures and options on futures above all, with forwards and swaps used occasionally, and the underlyings are typically equity and bond indexes together with commodities and currencies. As futures markets have grown in open interest and liquidity across different countries, some managers have added sector and industry index futures and more exotic contracts, including futures on weather variables such as temperature and rainfall, and derivatives on carbon emissions.

Investment characteristics

Because the returns are largely uncorrelated with stocks and bonds, adding managed futures to a traditional portfolio improves the risk-adjusted profile and pushes the efficient frontier outward in mean-variance terms. The value added has typically shown up during market stress. Through 2007 to 2009, these managers were short equity index futures and long bond futures at precisely the point when equities were selling off and bonds were rallying. That pattern is what positive skewness looks like in practice, and it is useful for offsetting strategies whose skew runs the other way.

The return profile is nonetheless very cyclical. From 2011 to 2018 currency and bond markets stopped trending, volatility drained out of many markets, and the acute stress episodes that this strategy feeds on simply stopped appearing. Outside equities in a handful of developed countries, most markets either went sideways or reverted, and performance suffered accordingly. There is also a subtler point: a trend in equities is, by construction, the least diversifying trend a portfolio of stocks and bonds could be given.

The correlation benefit has also changed now that sovereign yields have run down towards zero. Trend following fixed-income markets higher is unlikely to be as repeatable going forward. If managers begin trend following fixed-income markets lower, as developed market interest rates normalise, positive returns may still be realised, but with a very different and less valuable correlation behaviour against equity markets. Given the upward sloping shape of most global yield curves, there is also less natural fixed-income carry contribution from trend following those markets to the downside, meaning towards higher rates and lower prices.

Operationally, three features define the strategy: deep liquidity, activity spanning many asset classes, and the freedom to switch between long and short at will. Futures markets are among the most actively traded in the world. To take one measure, the daily dollar turnover in the CME E-mini equity index contract runs at 3 to 4 times that of SPY, the largest equity index fund on the planet. Futures also give highly liquid exposure to a wide range of asset classes traded across the globe 24 hours a day.

Because central clearinghouse management of margin and risk means futures contracts require relatively little collateral, long and short positions can be taken with higher leverage than with traditional instruments. Margin on a futures position, long or short, runs anywhere from 0.1% to 10% of the notional amount, against the 50% required on US equities. That is inherent leverage, and it is what makes managed futures managers able to be dynamic on both sides.

The financing structure differs fundamentally from a levered long-only portfolio. A long-only fund borrows cash and buys more assets with it. A futures fund owns nothing; what it holds is exposure equal to the notional value of its contracts. Most of the capital in the account, ordinarily 85% to 90% of it, sits in short-dated government paper or in whatever other liquid collateral the clearing house will accept, and the residual 10% to 15% collateralises the long and short futures positions.

Strategy implementation

Highly liquid contracts let these funds run a wide range of strategies. Nearly all of them rest on a pattern recognition trigger, driven either by momentum and trend or by a volatility signal, applied across several horizons at once, with a short-horizon mean reversion filter layered over the longer-horizon core.

A concrete illustration: a manager running a long-horizon model concludes that gold will trend lower, perhaps because the short moving average has crossed beneath the long one, and puts on a short in gold futures. Some time later a second model, running on a shorter horizon, reports that the downward momentum has faded and a bounce back towards the mean looks likely. The outputs of the two models are then blended into a single net position, with the long-horizon model carrying the greater weight and the short-horizon filter the lesser.

Carry relationships and volatility measures are frequently bolted onto the core momentum and breakout signals, and they earn their keep mainly in position sizing. Managers commonly set relative sizes by looking at two things together: how volatile each contract is, and how its returns move with the other contracts in the book. Both push the same way. A more volatile asset gets a smaller allocation, and so does an asset that moves closely with what is already held. Correlation analysis therefore becomes a second step, applied as a portfolio sizing risk constraint.

Beyond sizing, every managed futures manager needs an exit rule, and will use a price target exit, a momentum reversal exit, a time-based exit, a trailing stop-loss exit, or some combination of these. The key to running the strategy well is consistency of approach and the avoidance of overfitting when backtesting across different markets and time periods, since the goal is a model that performs in a future out-of-sample period. Trading models naturally degrade as more managers use similar signals and the opportunity diminishes, so managers constantly search for new and differentiated signals, increasingly built from nontraditional, unstructured data and other big data analysis.

Time-series against cross-sectional momentum

Away from the search for non-price signals, the most common managed futures approach is time-series momentum trend following, abbreviated TSM. Momentum strategies are driven by the past returns of the individual assets: managers go long assets rising in price and short assets falling in price. What matters in TSM is the absolute sign of the trend, so the book can sit net long or net short according to which way each asset is currently moving. It works best when the past returns of an asset are a good predictor of its own future returns.

A second, less common approach is cross-sectional momentum, abbreviated CSM. It ranks a group of assets, normally within one asset class, and buys the strongest while shorting the weakest. CSM strategies generally result in a net zero or market-neutral position. They work well when how a market has performed against its peers predicts how it will perform next. The practical limit is availability: at the asset class level there may simply not be enough listed contracts to form a proper cross-section.

The final question is the practical one: what happens to a traditional portfolio when a hedge fund strategy is added to it? The exercise takes one strategy category at a time, builds an equally weighted basket of every fund inside it, and drops a 20% slice of that basket into a 60% equity and 40% bond portfolio. Equities are proxied by the total return index for US large caps and bonds by the Bloomberg Barclays intermediate AA corporate index. The resulting combined allocation is 48% stocks, 32% bonds and 20% in the hedge fund strategy portfolio.

Treat this as an illustration rather than a recommendation. In practice it is unlikely that any investor would hold a 20% allocation consisting of an equal weighting of every live fund in a single strategy category.

This is a selection from the full set of 29 strategy portfolios examined. The baseline row is the traditional 60/40 portfolio against which each combined portfolio should be compared.

Return contribution

Against a traditional portfolio mean return of 6.96%, the best of the combined portfolios is the one holding US small cap long/short equity, at 7.53%, which is 57 bps better than the baseline. Three other allocations produce average annual returns above 7.30%: fixed-income arbitrage at 7.50%, distressed securities at 7.40% and systematic futures at 7.34%.

The broader pattern matters more than any single winner. A 20% slice of almost any of these strategies pulls the standard deviation of the whole portfolio down while lifting both risk-adjusted ratios, and roughly one combined portfolio in three also ends up with a smaller maximum drawdown. So hedge funds do two jobs at once in a stock and bond portfolio: they improve risk-adjusted return and they diversify.

Risk-adjusted contribution

The two ratios answer different questions. The Sharpe ratio defines risk as standard deviation, so it penalises upside and downside variability alike. The Sortino ratio counts only the variability that falls short of a minimum target, so upside movement is not penalised. Where a strategy is prone to large negative events, Sortino is the more informative of the two.

The best Sharpe ratio in the whole set, 0.83, belongs to the portfolio holding systematic futures. Close behind sit the portfolios holding distressed securities, fixed-income arbitrage, global macro and equity market neutral. On the Sortino ratio, the best combined portfolios by a wide margin come from allocations to equity market neutral in TASS, systematic futures, long/short equity hedge and event driven in TASS. Reading across both ratios, the strategies that improve risk-adjusted performance most are systematic futures, equity market neutral, global macro and the event-driven group. The implication for the multi-manager categories is uncomfortable: for all the breadth they can access, funds-of-funds and multi-manager vehicles add very little to risk-adjusted performance.

Risk reduction and drawdown

Many investors hold hedge fund strategies for risk reduction rather than return. Measured against a traditional portfolio standard deviation of 8.66%, the strategies producing the lowest combined portfolio standard deviations are systematic futures at 6.94%, and fund-of-funds macro/systematic and equity market neutral at a little more than 7.0%. Dedicated short bias and bear market equity are excluded from that comparison, because between them the two categories contain just 6 live funds and the statistics rest on a very thin sample. Those categories provide significant risk-reducing diversification, and they are the same categories that enhance risk-adjusted returns.

The other end is instructive too. Combined portfolios built around event-driven and distressed securities, or around relative value and convertible arbitrage, show relatively high standard deviations and therefore deliver little risk reduction. The explanations are structural. Most event-driven and distressed positions are long-biased with binary outcomes, and relative value and convertible arbitrage suffer forced deleveraging and liquidity problems whenever markets come under stress.

A drawdown is the gap between the peak value a portfolio has reached, its high-water mark, and the lowest point it touches before setting a new peak. Maximum drawdown is the largest such gap. Against a baseline maximum drawdown of 14.42%, the smallest figures belong to the opportunistic group, global macro and systematic futures in particular, joined by merger arbitrage and equity market neutral.

These findings knit back into the factor model. Those same strategies showed little equity or credit loading in the crisis window, and they also carry the lowest serial autocorrelation, which is the signature of genuinely liquid holdings. Risk mitigation for traditional assets therefore comes from three properties together: the risks are different ones, the approach is opportunistic, and the positions can be sold even when markets are under stress. At the opposite end, the long/short equity, event-driven and distressed, and relative value and convertible arbitrage groups all produce large maximum drawdowns once combined with the baseline portfolio. That is no surprise, given that the conditional model found equity risk sitting inside the event-driven and relative value books and credit risk turning significant in them once the crisis began.

Pulling the reading together

Three threads run through everything above. First, classification is a means to an end: the point of grouping strategies is to predict which risks a manager will import into a portfolio. Second, the fee structure is not a detail but a determinant of net outcomes, which is why netting risk and fee layering weigh so heavily against the fund-of-funds structure. Third, the risk you can see in normal conditions is not the risk you will face in a crisis, which is the entire argument for the conditional factor model. Strategies that stay liquid, avoid equity and credit exposure in a crisis, and carry low serial autocorrelation are the ones that genuinely mitigate risk in a traditional portfolio, and the historical evidence lands consistently on the opportunistic and market-neutral categories.