It’s easy to see why Warren Buffett is considered the greatest investor of all time. His company Berkshire Hathaway (NYSE: BRK-A) (NYSE: BRK-B) has become one of the most valuable in the world largely due to his investments, both in stocks and the companies he’s bought. Investors who were lucky or smart enough to buy Berkshire stock in its early days have become millionaires as shares gained an amazing 1,826,163% from 1965 to 2015. That’s an annual growth rate of 21.6%, more than double the 9.9% that the S&P 500 has returned in that time with dividends included.