Stocks that are expensive to borrow underperform significantly and for long periods of time. Every share must be held by an investor who does not lend it out and, hence, loses money. I find no evidence that investors hold these stocks in anticipation of lending them in the future. Instead, investors appear to hold these stocks for short-term trading. When turnover is high, high-fee stocks are overpriced and underperform. When turnover is low, high-fee stock prices are low, and they earn positive returns. More Robinhood investors hold shares when turnover is high than when it is low.

A short squeeze occurs if borrowed shares are recalled and the short seller is unable to find another source of shares. This forces the short seller to terminate a position early. For most stocks, the probability of a short squeeze is very low. Short squeezes, however, are not unusual for the hardest to borrow stocks. For these stocks, trading costs from squeezes are high and have a significant impact on the returns to short selling. For hard-to-borrow stocks, short sellers also miss out on significant abnormal returns because squeezes force them to close positions.

Short sale constrained stocks are overpriced on average. I show that firms exploit mispricing by selling shares when their stock is short sale constrained and repurchasing shares when their stock is easily shorted. Stocks underperform following seasoned equity offerings (SEOs) if and only if the stock is difficult to short. This suggests that some SEOs are motivated by mispricing, whereas others are not. Short selling costs make it difficult for investors to profit from the poor performance following SEOs. Short selling and SEOs are alternative ways to supply shares to investors, and firms become the low-cost share provider when short selling is costly.

Markets should be inefficient enough to allow returns to security analysis to adequately compensate the marginal analyst for his efforts. Cross-sectional differences in the costs of analysis therefore imply cross-sectional differences in market efficiency and in before-cost returns to smart investors. Small growth stocks are difficult to analyze and costly to trade. I find that the abnormal returns of mutual fund investments in small growth stocks from 1980 to 2006 averaged 0.76% per month. Large value stocks are easier to analyze and cheaper to trade. Mutual funds earned average monthly abnormal returns of only 0.05% in large value stocks during the same period.

We document by several methods that trading in Nasdaq stocks is localized, but find little evidence that cloudy weather in the city in which a company is based affects its returns. The first evidence of localized trading is that the time zone of a company's headquarters affects intraday trading patterns in its stock. Second, firms in blizzard-struck cities see a dramatic trading volume drop compared to firms in other cities. Third, the Yom Kippur holiday dampens trading volume in companies located in cities with high Jewish populations. Despite the strong evidence of localized trading, cloudy conditions near the firm's headquarters do not provide profitable trading opportunities.