To illustrate that not all mutual fund returns are created equal, I present you with the Monte Carlo simulation for Fidelity's Low-priced Stock (FLPSX) mutual fund. I've been a long term investor in FLPSX and discovered that the returns are just skewed 57% toward the positive side for the past 10 years.
However, if you look at the histogram distribution for FLPSX, you'll see a lot of observations are lumped on the negative side. Despite the odds being in my favor, the payoff might not be worth the risk I'm taking. I'm not sure if I want to expose myself to all that risk and I'm considering lightening up my position in FLPSX!