Ken Griffin is arguably one of the most successful investors of all time. He made a name for himself when he shorted stocks just ahead of the 1987 market crash that came to be known as "Black Monday." His profits last year topped $7 billion as his returns of roughly 15% outpaced many of his peers.

Any list of the greatest hedge fund managers of all time should include Ken Griffin. Today, Citadel ranks among the largest and most successful hedge funds in the U.S. And Griffin is worth around $46.

Billionaire Ken Griffin cast doubt on two of President-elect Donald Trump’s most loudly heralded economic policy plans: tax cuts and tariff hikes.

Citadel Advisors, run by billionaire investor Ken Griffin, is one of the most prestigious hedge funds on Wall Street, and while reviewing the 13F it filed on Nov. 14, I noticed something. In the third quarter, the fund increased its stake by 172% in a semiconductor stock that isn't Nvidia.

I am gravely concerned that the rise of tariffs puts us on a slippery slope towards crony capitalism,” the billionaire investor said.

I am gravely concerned that the rise of tariffs puts us on a slippery slope towards crony capitalism,” the hedge fund billionaire told reporters.

And while taking a spin through Citadel's most recent 13F filing, I noticed Griffin and his firm scooped up 1.2 million shares of electric vehicle (EV) manufacturer Tesla ( TSLA -1.15%) during the third quarter, increasing the fund's position by 395%.