Fund managers determine appropriate liquidity buffers by combining quantitative stress testing, qualitative assessment of investor behaviour, and regulatory guidance. They aim to ensure that redeeming investors can be paid without forcing fire sales that depress market prices and harm remaining shareholders. Research by Gary Gorton Yale University highlights how runs in open-ended vehicles can transmit stress to markets, underscoring the systemic importance of robust buffers.
Stress scenarios and quantitative methods
Quantitative methods start with forward-looking stress testing that models sudden or sustained redemption scenarios. Managers project redemptions using historical episodes and idiosyncratic triggers, then map those out against the liquidity profile of holdings. They evaluate market depth, bid-ask spreads, and time-to-liquidate for each security, adjusting for periods of extreme illiquidity when normally tradeable assets can become hard to sell. Darrell Duffie Stanford University explains how liquidity spirals amplify sales into price declines, which is why assumptions about price impact and contagion are central to buffer sizing.
Investor behaviour and structural factors
Qualitative assessment examines investor concentration, share-class features, and the fund’s distribution channels. Funds with a few large institutional investors or with gateable redemption terms may behave differently from retail-heavy funds that can exhibit herd behaviour. Regulators and standard-setters such as the Financial Stability Board recommend that managers account for these behavioural and structural features when setting buffers, because they change the probability and intensity of redemption stress.
Managers also consider available liquidity management tools—swing pricing, redemption gates, notice periods, and side pockets—and the legal and operational feasibility of deploying them quickly. IOSCO recommends operational readiness alongside buffer planning. The International Monetary Fund notes that emerging markets often require larger cash cushions or more conservative liquidation assumptions because local market depth and cross-border settlement frictions increase execution risk.
Consequences of under-sizing buffers include forced asset sales, amplified market volatility, dilution of remaining investors, and potential regulatory intervention. Over-sizing buffers, however, can reduce portfolio returns and limit investor access, creating trade-offs between resilience and investor utility. Effective practice integrates continuous monitoring, scenario updates after market events, and governance oversight to align buffer policy with the fund’s mandate, investor base, and the broader market context.