What type of market efficiency—none, weak, semi-strong, or strong—exists under each of the following statements?
a) I know which stocks are going to rise in value by looking at their price changes over the past two weeks.
b) Returns earned by company officers trading their own firm’s stock are no better than those of other investors.
c) If a firm announces lower-than-expected earnings, you know the price will fall over the next quarter.
d) By the time I heard the news about the dividend increase the stock had already risen by a substantial amount.
e) Whatever the stock market does in January, it will continue to move in that direction for the rest of the year.
f) As soon as the chairman of the Federal Reserve give his testimony to Congress about future monetary policy, interest rates rose and stock prices dropped.