U.S. stocks dropped as investors began May pondering profit warnings tied to the coronavirus and a ratcheting up of tension with China. The dollar rose as a risk-off mood prevailed.

The S&P 500 Index fell almost 3 per cent, leaving it a tad lower for the week, after sobering comments from Amazon.com Inc. and Apple Inc. about the pandemic’s impact. Exxon Mobil Corp. slumped after posting its first quarterly loss in at least 32 years. The dollar posted its first increase since last week.

The Dow Jones Industrial Average fell 617.09 points, or 2.53 per cent, to 23,728.63, the S&P 500 lost 81.13 points, or 2.79 per cent, to 2,831.3 and the Nasdaq Composite dropped 284.60 points, or 3.2 per cent, to 8,604.95. The TSX was down 160 point at 14,620.

Equities also retreated in the U.K., one of the few open markets in Europe as other countries celebrated May Day, and the pound gave back some of this week’s gains as Prime Minister Boris Johnson pledged a “comprehensive plan” to lift the country’s lockdown, with details due next week.

While the S&P 500 posted its best month since 1987 in April — spurred by a slowdown in coronavirus infections and $8 trillion in promised stimulus initiatives globally — earnings reports and economic data are serving a reminder of lasting pain. Amazon warned of a possible second-quarter loss, while Apple omitted an earnings forecast for the first time in more than a decade. Federal Reserve Bank of Dallas President Robert Kaplan warned of a “severe” contraction from the effects of coronavirus.

“Earnings continued to be a minefield,” said Bryce Doty, portfolio manager at Sit Investment Associates Inc. “You don’t really know what is going to happen because there is so little clarity.”

The advance in the dollar followed U.S. President Donald Trump reviving an attack on China, speculating it could have spread the coronavirus and threatening trade tariffs. Trump is exploring blocking a government retirement fund from investing in Chinese equities considered a national security risk, a person familiar with the internal deliberations said.

Elsewhere, West Texas oil posted its first weekly gain in about a month as global production cuts began to take effect.

Stocks slumped in Tokyo and Sydney. Most Asian markets didn’t trade.