The Dow Jones industrial average dropped as much as 140.82 points, or 0.5 percent, to 25,242.29 at the open, while the S&P 500 fell as much as 0.4 percent and the tech-heavy Nasdaq lost as much as about 0.3 percent.

The tumble followed a weekend of violent protests across the nation sparked by the police killing of George Floyd in Minneapolis. It also came as China promised retaliation against President Trump’s move to start ending the US’s special trade relationship with Hong Kong.

“Uncertainty over the reopening of the US economy from the coronavirus-driven lockdowns, coupled with trade tensions and violent protests in major cities across the country is a worrisome combination for markets,” said David Trainer, CEO of investment research firm New Constructs.

The growing tensions at home and abroad helped slow Wall Street’s rally over the last two months amid optimism about the economy emerging from lockdowns meant to control the coronavirus. The S&P ended May just about 10.3 percent below its all-time high reached in February, before the pandemic tanked global markets.

But global markets rose Monday given that Trump’s Friday strike at Beijing left the landmark US-China trade deal unscathed. Hong Kong’s Hang Seng index closed up 3.3 percent, while London’s FTSE 100 was recently up 0.7 percent.

With Post wires