Answer the following questions and explain your answers in details:
Explain why any test of market efficiency is always a joint test.
Very risky stocks on average yield higher returns than relatively safe stocks.
Is this a violation of market efficiency?
Stocks that have appreciated unusually in the recent past continue to do so. Is this a violation of market efficiency?
A successful firm like Microsoft has consistently generated large profits for years. Is this a violation of market efficiency?
You can earn abnormal returns by buying stocks in December and selling them in January. Which form of market efficiency does this strategy violate?