Initial margin requirements represent: (1) a cost impediment to the wealth constrained investor and (2) a potential way of mitigating excessive volatility. However, prior empirical research finds that margins are not an effective tool in reducing volatility. We consider the possibility that...

Using a sample of over 3,000 seasoned equity offerings (SEOs) from 1983 to 1998, we test the hypothesis that the U.S. Securities and Exchange Commission's Rule 10b-21, which disallows the covering of short positions with newly issued SEOs, makes pre-offer stock prices less informative, which, in...