I develop a framework to analyze demand curves for multiple risky securities at extended horizons in a setting with limits-to-arbitrage. Following an unexpected change in uninformed investor demand for several assets, I predict returns of each security to be proportional to the contribution of that security's demand shock to the risk of a diversified arbitrage portfolio. I show that securities that are not affected by demand shocks but are correlated with securities undergoing changes in demand should experience returns related to their hedging role in arbitrageurs' portfolios. Finally, I predict a negative cross-sectional relation between post-event returns and the initial return associated with the change in demand. I confirm these predictions using data from a unique redefinition of the Nikkei 225 index in Japan, in which 255 stocks simultaneously undergo significant changes in index investor demand, causing more than ¥2,000 billion of trading in one week and large price changes followed by subsequent reversals for all of the reweighted stocks.

I examine a series of stock splits in Japan in which firms restrict the ability of their investors to sell their shares for a period of approximately 2 months. By removing potential sellers from the market, the restrictions have the effect of increasing the impact of trading on prices. The greater the desire of investors to trade, and the greater the restrictions, the larger the impact of the restrictions. In the data, particularly severe restrictions are associated with returns of over 30% around the ex-date, most of which are reversed when investors are allowed to sell again. Firms are more likely to issue equity or redeem convertible debt during the restricted period, suggesting strong incentives for manipulation.

[I examine a series of stock splits in Japan in which firms restrict the ability of their investors to sell their shares for a period of approximately 2 months. By removing potential sellers from the market, the restrictions have the effect of increasing the impact of trading on prices. The greater the desire of investors to trade, and the greater the restrictions, the larger the impact of the restrictions. In the data, particularly severe restrictions are associated with returns of over 30% around the ex-date, most of which are reversed when investors are allowed to sell again. Firms are more likely to issue equity or redeem convertible debt during the restricted period, suggesting strong incentives for manipulation.]

[Relative to their weights in a value-weighted index, a number of stocks in Japan's Nikkei 225 stock index are overweighted by a factor of 10 or more. I document a strong positive relation between overweighting and the comovement of a stock with other stocks in the Nikkei index, and a negative relationship between index overweighting and comovement with stocks outside of the index. The cross-sectional approach resolves endogeneity problems associated with event study demonstrations of excess comovement. A trading strategy that bets on the reversion of stock prices of overweighted stocks generates economic profits, confirming that the observed comovement patterns are excessive, and providing further evidence that comovement of stock returns can be a consequence of commonality in trading behavior.]

Relative to their weights in a value-weighted index, a number of stocks in Japan's Nikkei 225 stock index are overweighted by a factor of 10 or more. I document a strong positive relation between overweighting and the comovement of a stock with other stocks in the Nikkei index, and a negative relationship between index overweighting and comovement with stocks outside of the index. The cross-sectional approach resolves endogeneity problems associated with event study demonstrations of excess comovement. A trading strategy that bets on the reversion of stock prices of overweighted stocks generates economic profits, confirming that the observed comovement patterns are excessive, and providing further evidence that comovement of stock returns can be a consequence of commonality in trading behavior. The Author 2007. Published by Oxford University Press on behalf of The Society for Financial Studies., Oxford University Press.

Recent work documents large positive abnormal returns when a hedge fund announces activist intentions regarding a publicly listed firm. We show that these returns are largely explained by the ability of activists to force target firms into a takeover. For a comprehensive sample of 13D filings by portfolio investors between 1993 and 2006, announcement returns and long-term abnormal returns are high for targets that are ultimately acquired, but not detectably different from zero for firms that remain independent. Firms targeted by activists are more likely than control firms to get acquired. Finally, activist investors’ portfolios perform poorly during a period in which market wide takeover interest declined.

We analyze time series of investor expectations of future stock market returns from six data sources between 1963 and 2011. The six measures of expectations are highly positively correlated with each other, as well as with past stock returns and with the level of the stock market. However, investor expectations are strongly negatively correlated with model-based expected returns. The evidence is not consistent with rational expectations representative investor models of returns.

We analyze time-series of investor expectations of future stock market returns from six data sources between 1963 and 2011. The six measures of expectations are highly positively correlated with each other, as well as with past stock returns and with the level of the stock market. However, investor expectations are strongly negatively correlated with model-based expected returns. We reconcile the evidence by calibrating a simple behavioral model, in which fundamental traders require a premium to accommodate expectations shocks from extrapolative traders, but markets are not efficient.

We examine empirically how the supply and maturity structure of government debt affect bond yields and expected returns. We organize our investigation around a term-structure model in which risk-averse arbitrageurs absorb shocks to the demand and supply for bonds of different maturities. These shocks affect the term structure because they alter the price of duration risk. Consistent with the model, we find that the maturity-weighted-debt-to-GDP ratio is positively related to bond yields and future returns, controlling for the short rate. Moreover, these effects are stronger for longer-maturity bonds and following periods when arbitrageurs have lost money.

[We show that the credit quality of corporate debt issuers deteriorates during credit booms and that this deterioration forecasts low excess returns to corporate bondholders. The key insight is that changes in the pricing of credit risk disproportionately affect the financing costs faced by low-quality firms, so debt issuance of low-quality firms is particularly useful for forecasting bond returns. We show that a significant decline in issuer quality is a more reliable signal of credit market overheating than rapid aggregate credit growth. We use these findings to investigate the forces driving time variation in expected corporate bond returns.]