We use mutual fund flows as a measure of individual investor sentiment for different stocks, and find that high sentiment predicts low future returns. Fund flows are dumb money–by reallocating across different mutual funds, retail investors reduce their wealth in the long run. This dumb money effect is related to the value effect: high sentiment stocks tend to be growth stocks. High sentiment also is associated with high corporate issuance, interpretable as companies increasing the supply of shares in response to investor demand.

Does corporate diversification reduce shareholder value? Since firms endogenously choose to diversify, exogenous variation in diversification is necessary to draw inferences about the causal effect. We examine changes in the within-firm dispersion of industry investment, or “diversity”. We find that exogenous changes in diversity, due to changes in industry investment, are negatively related to firm value. Thus diversification destroys value, consistent with the inefficient internal capital markets hypothesis. Measurement error does not cause this finding. We also find that exogenous changes in industry cash flow diversity are negatively related to firm value.

Stocks can be overpriced when short-sale constraints bind. We study the costs of short-selling equities from 1926 to 1933, using the publicly observable market for borrowing stock. Some stocks are sometimes expensive to short, and it appears that stocks enter the borrowing market when shorting demand is high. We find that stocks that are expensive to short or which enter the borrowing market have high valuations and low subsequent returns, consistent with the overpricing hypothesis. Size-adjusted returns are 1–2% lower per month for new entrants, and despite high costs it is profitable to short them.

We examine the reaction of daily Treasury bond prices to the release of U.S. macroeconomic news. These news releases (of employment and producer price index data) are of interest because they are released on periodic, preannounced dates and because they are associated with substantial bond market volatility. We investigate whether these nonautocorrelated announcements give rise to autocorrelated volatility. We find that announcement-day volatility does not persist at all, consistent with the immediate incorporation of information into prices. We also find a risk premium on these release dates.