THE REVERSAL OF LARGE STOCK-PRICE DECREASES

Extremely large negative 10‐day rates of return are followed on average by larger‐than‐expected positive rates of return over following days. This price adjustment lasts approximately 2 days and is observed in a sample of firms that is largely devoid of methodological problems that might explain the reversal phenomenon. While perhaps not representing abnormal profit opportunities, these reversals present a puzzle as to the length of the price adjustment period. Such a slow recovery is inconsistent with the notion that market prices quickly reflect relevant information. 1991 The American Finance Association