Stocks on Wall Street fell sharply Friday as confirmed new coronavirus infections in the U.S. hit an all-time high, prompting Texas and Florida to reverse course on the reopening of businesses.

The combination injected new jitters into a market that's been mostly riding high since April on hopes that the economy will recover from a deep recession as businesses open doors and Americans begin to feel more confident that they can leave their homes again.

The S&P 500 dropped 2.4%, giving up all of its gains after a rally the day before. The sell-off capped a choppy week of trading that erased the...