Suppose that an investor is considering whether to keep a stock in his portfolio, buy more of it, or sell it. The investor requires a 10% rate of return from that stock. If the stock is expected to...

Suppose that an investor is considering whether to keep a stock in his portfolio, buy more of it, or sell it. The investor requires a 10% rate of return from that stock. If the stock is expected to give a rate of return of 11%, what action should the investor take? What should happen if the stock’s expected rate of return is exactly 10%?