NEW YORK (AFP) - US stocks tumbled on Tuesday (Oct 11) as disappointing Alcoa results sharpened concerns about the just-under-way third-quarter earnings season.

Alcoa slumped 11.4 per cent missing earnings-per-share expectations and offering a lackluster forecast for its value-added aluminum businesses, which will be renamed "Arconic" when the company splits in two on Nov 1.

The market is "very cautious" on earnings after five straight quarters in which the S&P 500 reported declining profits, said David Levy portfolio manager at Republic Wealth Advisors.

Analysts also cited lower oil prices and higher government bond yields as concerns.

At the closing bell, the Dow Jones Industrial Average was at 18,128.66, down 1.1 per cent.

The broad-based S&P 500 shed 1.2 per cent to 2,136.73, while the tech-rich Nasdaq Composite Index sank 1.5 per cent to 5,247.10.