Stock market mutual funds offer investors diversified stock market portfolios, but there are several types. Actively managed funds attempt to “beat” the market by using research, forecasts, and judgment to pick stocks with the best growth prospects. Passively managed funds attempt to replicate the market by buying a representative sample of the stocks on a specific stock market index. Which to choose? The April 2016 issue of Page One Economics explains the efficient market hypothesis and how it might influence your investment decisions.