"You get a betting advantage." Actually you don't. The investment industry understands very well that people will naively invest based on superior historical p

"You get a betting advantage." Actually you don't. The investment industry understands very well that people will naively invest based on superior historical performance, so they use that history to sell investment products. One example of a popular rating system is the Morningstar Rating which rates a fund, stock, or manager based on performance over e.g. 3, 5, 10 years. But that history is public information that most investors use already, so it cannot convey a betting advantage. "you will make money when the person really was a smart investor" Statistically speaking, you will run out of money long before you find this hypothetical smart investor. Also, note that the smart investor has not necessarily been "successful" in the past. He could very well have been accumulating shares or fund units while prices were falling, anticipating that they will rise in the future. Point is, unless you know why that investor is smart, you are essentially leaving it all to chance.