It's obvious, other wise all investors and capitalist are already rich now, the fact that not all who invested are successful and I mean many of them. Investing is not an easy venture, it's full of risk and only those who are knowledgeable enough will succeed.
Those who are rich because of their investment are visionary enough to know the movement especilly in stocks. Also, they are risk takers who believe it will succeed. All investment ahs risks, we accept it. But if you take a risk, nothing will happen.