the 10%~15% average for broad market is based on SP history performemce. It's like 12% historically.

On a side note, 75% mutual fund can't beat market average return. Which means, each year 3 of 4 fund manager's performance is worse than market.

For smart money, they goes to hedge fund or other higher return investment. Mutual fund managers are full of sucks. But it does have one benefit, the risk is much lower.

It's good for retirement planing, to keep your hard earned money value, at least balance out the inflation.