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?