Early studies find that option introductions tend to raise the price of underlying stocks. More recent research indicates that post-1980 option introductions are associated with negative abnormal returns in underlying stocks. Other studies document increased short sale activities following option listing. This paper provides evidence that the documented abnormal returns and changes in short interest around option listings are consistent with the mitigation of short sale constraints resulting from the option introduction, and that both the abnormal returns and short interest changes around listing dates can be predicted using ex ante characteristics of the underlying stock.

We analyze the price reaction to analysts' revisions by testing the Griffin and Tversky (1992) hypothesis that agents place emphasis on the strength of the signal (the dramatic nature of the event) and may de-emphasize the weight (the ability of the analyst making the recommendation). Two attributes, namely, years of experience and the reputation of the analysts' brokerage houses form proxies for analyst ability (or weight) that we validate by documenting that revisions by high ability analysts outperform those by low ability ones. We find evidence of return persistence following small (low strength) revisions by high ability analysts and the opposite return pattern following large (high strength) revisions of low ability analysts, consistent with the arguments of Griffin and Tversky (1992). Our study provides an empirical link between evidence on individual decision making and stock market returns, and also helps promote an understanding of the analyst industry as well as its interaction with the investing population.

Miller (1977) hypothesizes that dispersion of investor opinion in the presence of short-sale constraints leads to stock price overvaluation. However, previous empirical tests of Miller's hypothesis examine the valuation effects of only one of these two necessary conditions. We examine the valuation effects of the interaction between differences of opinion and shortsale constraints. We find robust evidence of significant overvaluation for stocks that are subject to both conditions simultaneously. Stocks are not systematically overvalued when either one of these two conditions is not met.

Efficiency in the capital markets requires that capital flows are sufficient to arbitrage anomalies away. We examine the relation between flows to a quantitative (quant) strategy that is based on capital market anomalies and the subsequent performance of this strategy. When these flows are high, quant funds are able to implement arbitrage strategies more effectively, which in turn leads to lower profitability of market anomalies in the future, and vice versa. Thus, the degree of cross-sectional equity market efficiency varies across time with the availability of arbitrage capital.