US stocks ended sharply lower on Monday, with the S&P 500 and the Nasdaq closing below a key technical indicator for the first time since late April as investors braced for quarterly results from retailers and chip giant Nvidia and awaited a long-delayed US jobs report this week.

Losses accelerated in afternoon trading as all three main indexes traded below their 50-day moving averages. This closely followed moving average is seen as a proxy for the intermediate-term trend.

The Dow closed below its 50-day moving average for the first time since October 10.

Results this week from major retailers Walmart, Home Depot and Target will round out the quarterly earnings season.

Shares of Home Depot, due to report on Tuesday before the bell, ended 1.2 percent lower.

Investors eagerly awaited the September jobs report, which is due to be released on Thursday after the long US government shutdown ended last week.

Investors are waiting for two big things: "a look at the consumer... and Nvidia's earnings," said Adam Sarhan, chief executive of 50 Park Investments in New York, noting that "you have a consumer that is potentially getting weaker, not stronger."

Also, he said, the market is consolidating after strong gains this year. The S&P 500 remains up 13.4 percent for the year to date.

Nvidia, the world's largest company by market value, which is at the heart of Wall Street's artificial intelligence trade, is due to report after the bell on Wednesday. Its shares fell 1.9 percent on Monday and were the biggest drag on the Nasdaq and S&P 500.

Stocks have been pressured this month by concerns that AI exuberance has driven up valuations to expensive levels.

The Dow Jones Industrial Average fell 557 points, or 1.2 percent, to 46,590, the S&P 500 lost 61 points, or 0.9 percent, to 6,672 and the Nasdaq Composite lost 192 points, or 0.8 percent, to 22,708.

It was the first time the S&P 500 and Nasdaq closed below their 50-day moving averages since April 30.

Among the day's gainers, Google parent Alphabet rose 3.1 percent after Berkshire Hathaway revealed a stake of US$4.3 billion in the company.

Berkshire also further reduced its stake in Apple, whose shares ended 1.8 percent lower on Monday. Among other declining shares, Dell Technologies dropped 8.4 percent and Hewlett Packard Enterprise fell 7 percent, both after Morgan Stanley ratings downgrades. (Reuters)