In this paper we examine the ex-dividend day returns of several taxable and non-taxable distributions. The ex-dividend day returns for the taxable common stocks are consistent with the hypothesis that dividends are taxed more heavily than capital gains. However, the ex-dividend day returns of preferred stocks suggest that preferred dividends are taxed at a lower rate than capital gains; non-taxable stock dividends and splits are priced on ex-dividend days as if they are fully taxable; and non-taxable cash distributions are priced as if investors receive a tax rebate with them. We also find that each of these distributions exhibits abnormal return behavior for several days surrounding the ex-dividend day. We investigate several possible explanations for this anomaly, but none is capable of explaining the phenomenon.