Which of the following hypothetical phenomena would be either consistent with or a violation of the efficient market hypothesis? Explain briefly.

a. Nearly half of all professionally managed mutual funds are able to outperform the S&P 500 in a typical year.

b. Money managers who outperform the market (on a risk-adjusted basis) in one year are likely to outperform the market in the following year.

c. Stock prices tend to be predictably more volatile in January than in other months.

d. Stock prices of companies that announce increased earnings in January tend to outperform the market in February.