Long-short strategy
What is Long-short strategy?
A long-short strategy owns assets expected to outperform and shorts assets expected to underperform, managing the gross and net exposure created by both sides.
Gross and net exposure should be supplemented with beta, factor, sector, liquidity, and scenario exposure. A balanced dollar book can still carry large momentum, quality, growth, or crowding bets. Investors should examine whether short alpha survives borrow and whether long alpha survives financing and fees. Capacity often deteriorates first on the short side, precisely where managers may claim their strongest information advantage.
How it works
Long positions gain when prices rise, while shorts generally gain when borrowed securities are sold and later repurchased lower. Net exposure is longs minus shorts and gross exposure is the sum of their absolute values. A 130% long and 70% short portfolio has 60% net and 200% gross exposure before derivatives.
Sources of return
Return can come from market direction, factor tilts, spread between longs and shorts, financing, and portfolio construction. Correct relative selection can still lose if market beta overwhelms it. Short rebates, borrow fees, dividends owed, recalls, and trading costs reduce results. Gross exposure can magnify both intended alpha and unintended factor or crowding risk.
Example
A manager buys one retailer and shorts another in equal dollars. The long falls 5%, but the short falls 15%, producing a positive relative spread before costs. If both rise sharply and the short becomes hard to borrow, losses and collateral needs can escalate despite low initial net exposure.
How to evaluate one
Review long and short books separately by issuer, sector, factor, liquidity, catalyst, and conviction. Track gross, net, beta-adjusted, concentration, turnover, borrow, and crowding. Attribution should identify whether results came from longs, shorts, market direction, or factors. Understand how the manager sizes asymmetric short risk and handles corporate actions.
Risks and practical checklist
Short losses can be unlimited in theory, and borrow can be recalled or become costly. Leverage, squeezes, gaps, dividends, and forced covering can impair the strategy. Confirm prime brokers, collateral, locate process, and liquidity. Stress correlated long declines and short rallies, and never treat low net exposure as low risk when gross exposure and concentration are high.
Sources and further reading
- Investment Products, Investor.gov, U.S. Securities and Exchange Commission