US stocks tumbled Wednesday led by tech shares as a key oil stockpiles report and the Federal Reserve's Beige Book pointed to more sluggish US economic growth. The blue-chip Dow Jones Industrial Average lost 364.81 points, or 2.21 per cent, to 16,151.41. The S&P 500 sank 48.40 points, or 2.50 per cent, to 1,890.28, while the Nasdaq Composite lost 159.85 points, 3.41 per cent, at 4,526.06. There was no clear catalyst for the sell-off, after Wall Street opened with a buoyancy that gave hope to a third straight gain.