4.A technical analyst is on trial for claims they are making:

a)In a certain stock, the analyst claims there is momentum in the prices.You know for a fact this stock price is a martingale.Can the analyst be correct?

b)In a different stock, the analyst claims that there is mean reversion in the stock prices; more specifically, the stock prices follow an unbiased random walk.You know for a fact that this stock is a martingale.Can the analyst be correct?