Warren Buffett is commonly regarded as the one of the greatest investors in American history. That's because Berkshire Hathaway ( BRK.A 0.56%) ( BRK.B 0.53%) stock has returned 19.9% annually since he took control six decades ago. Comparatively, the S&P 500 ( ^GSPC 1.12%) has returned 10.4% annually during the same period.

It looks like it’s Warren Buffett’s turn to say, “I told you so.” Late last year, the Berkshire Hathaway CEO was busy selling stocks when the S&P 500 logged more than 50 record closes, leading many market observers to scratch their heads.

Warren Buffett is losing control of Berkshire Hathaway, and hedge fund manager Bill Ackman says it’s time for a new era. The 94-year-old “Oracle of Omaha” has