Stocks sank on Tuesday as enthusiasm over a potential coronavirus vaccine dampened and major companies reported earnings.
The Dow Jones Industrial Average closed down 391 points, or 1.6 points, and the S&P 500 closed down 31 points, or 1.1 percent.
The drops followed an ebullient Monday, which saw the Dow up more than 900 points on news that biotech Moderna had seen positive indications about a vaccine for coronavirus.
On Tuesday, stocks sank lower after a report in STAT News raised questions about whether Moderna released enough information to support the conclusion that its vaccine trials were going as positive as it had portrayed.
The report noted that the company had released little data to accompany its claims, and more pointedly indicated that the reported immune response had shown up just two weeks after the vaccinations, giving little indication of how long the immune response might last.
The drops also followed earnings reports by major companies including Walmart, Home Depot, and Kohls. While Home Depot and Kohls suffered losses through the pandemic, Walmart said its online sales had soared 74 percent as lockdowns took hold.
A report from the Congressional Budget Office on Tuesday indicated that the economy would not simply bounce back once the pandemic was under control.
It projected that unemployment would remain at an average of 9.3 percent in 2021, and that GDP would still be 1.6 percent lower by the end of 2021 than it was at the end of 2019.