Liquidity Shocks, Systemic Risk, and Market Collapse: Theory and Application to the Market for Perps

Traditional explanations of market crashes rely on the collapse of an asset price bubble or the exacerbation of an information asymmetry sufficient to cause less-informed participants to withdraw from the market. We show that markets can crash even though asset prices have not deviated from fundamental values and information is shared symmetrically among all market participants. We present a model in which markets crash when investors shift their beliefs about the liquidity of the secondary market. While such shifts in liquidity may be a factor in explaining many market crashes, the collapse of the market for perpetual floating-rate notes (perps) provides an especially clear illustration of the theory because a shift in liquidity beliefs appears to have been the sole determinant of the market crash. Such a shift can be precipitated by a systemic liquidity shock that is transitory or permanent. The latter proved to be the case with perps because perceptions of the liquidity of the secondary market were permanently altered. In addition to providing new insights into why markets crash, our findings are particularly relevant for unseasoned financial products that are often priced and marketed on the assumption that liquid secondary markets will develop. The perp episode also highlights the importance of broad placement of securities. Since market liquidity arises endogenously from the diversity of liquidity needs across the investor base, the broader the investor base, the lower the probability of a systemic liquidity shock. We also show how simple modifications in security design can mitigate the impact of such a shock should it occur.