Stocks ended lower on Wall Street Friday, giving up their gains for the week, after Amazon and other big companies laid out how the coronavirus pandemic is hitting their bottom lines.

The S&P 500 index fell 2.8%. Amazon sank after its profits fell because of a sharp increase in costs related to providing deliveries safely during the pandemic, despite a big increase in revenue.

Bond yields held steady and the price of oil rose slightly. Many world markets were closed for the May Day holiday.

On Thursday the S&P 500 closed out its biggest monthly gain since 1987.