Prices are pretty well modeled using Brownian motion. Most economists should know this while almost no one in the normal population will be aware of it. Sometimes people are just lucky, but overall the more trades you make the more you'll converge on the average return rate.
I would also like to note, that predicting price is different from predicting an overall increase in the value of the underlying security.
I would also like to note, that predicting price is different from predicting an overall increase in the value of the underlying security.
https://en.wikipedia.org/wiki/Brownian_model_of_financial_ma...