This study evaluates the effect of SEC-ordered suspensions on securities' returns, volatility, and trading volume during 1963-87. It is found that there is a permanent devaluation of these securities during the suspension. This result, however, is sensitive to the announced reason for the...

This study examines the effect of changes in margin requirements on stock price volatility. The authors examine the possibility that the impact of margin requirements varies with a stock's degree of speculative interest. Using four alternative measures of speculative interest, the authors divide...