"You're losing one of the most esteemed investors one could argue of all time," a source said of investors' reaction to Buffett's plan to step down.

Buffett, one of the world’s richest people and most accomplished investors, took control of Berkshire Hathaway in 1965 when it was a textiles manufacturer. He turned the company into a conglomerate by finding other businesses and stocks to buy that were selling for less than they were worth.

What is Buffett’s legacy?Start the day smarter. Get all the news you need in your inbox each morning. Buffett took over Berkshire in 1965 with a value approach to investing. Value investing includes focusing on identifying and purchasing stocks that are trading below their perceived intrinsic or fair value.