U.S. stocks slid Wednesday as the White House readied new tariffs. The S&P 500 fell 64.45 points, 1.1%, to close at 5,712.20, while the blue-chip Dow gave back 132.71 points, 0.3%, to hit 42,454.79.

Billionaire investors are in an unfamiliar position, watching and cringing as tariffs roll on and the stock market reels.