During a financial crisis, when investors are most in need of liquidity and accurate prices, hedge funds cut their arbitrage positions and hoard cash. The paper explains this phenomenon. We argue that the fragile nature of the capital structure of hedge funds, combined with low market liquidity, creates a risk of coordination in redemptions among hedge fund investors that severely limits hedge funds' arbitrage capabilities. We present a model of hedge funds' optimal asset allocation in the presence of coordination risk among investors. We show that hedge fund managers behave conservatively and even abstain from participating in the market once coordination risk is factored into their investment decisions. The model suggests a new source of limits to arbitrage.

The 1987 market crash was associated with a dramatic and permanent steepening of the implied volatility curve for equity index options, despite minimal changes in aggregate consumption. We explain these events within a general equilibrium framework in which expected endowment growth and economic uncertainty are subject to rare jumps. The arrival of a jump triggers the updating of agents' beliefs about the likelihood of future jumps, which produces a market crash and a permanent shift in option prices. Consumption and dividends remain smooth, and the model is consistent with salient features of individual stock options, equity returns, and interest rates.

We examine the effect of directors' and officers' liability insurance (D&O insurance) on the outcomes of merger and acquisition (M&A) decisions. We find that acquirers whose executives have a higher level of D&O insurance coverage experience significantly lower announcement-period abnormal stock returns. Further analyses suggest that acquirers with a higher level of D&O insurance protection tend to pay higher acquisition premiums and their acquisitions appear to exhibit lower synergies. The evidence provides support for the notion that the provision of D&O insurance can induce unintended moral hazard by shielding directors and officers from the discipline of shareholder litigation.