All-clear or just a break in the sell-off? That’s the question investors are grappling with as U.S. stocks roared back from the worst rout in four months.

A day after plunging as much as 1.9% on concern the deadly coronavirus will disrupt the global economy, the S&P 500 jumped more than 1%, the first back-to-back opposite moves of 1% since late August. There’s reason for optimism, as China moved to contain the outbreak, but past instances of wild daily stock swings show an immediate return to calm is unlikely.

Take early August, when the S&P 500 plunged 3% after China escalated the trade war with the U.S. by devaluing the yuan. It surged almost 4% in the next three sessions, only to suffer a sell-off of nearly 3% a few days later. Or a 1.9% rally in the S&P in October 2018 after 3.1% loss the day before. The index went on to lose anointer 12% in the next two months. Or a 1.7% gain in the S&P 500 in February 2018 after six-day rout. The index shed another 4.2% in the next two sessions and went nowhere in the next eight months.

“What we’re seeing today is your typical move in a wildly volatile situation in which it’s impossible to get the timing right,” said Michael Antonelli, a managing director and market strategist at Robert W. Baird & Co. “People have been saying for months that we’re due for a pullback. The virus isn’t going away any time soon, and if things get worse, that might be the catalyst for a further sell-off.”

Even if China succeeds in mitigating the virus’s impact on the economy, the coming days will are loaded with earnings reports, economic data and the Federal Reserve’s policy meeting. Apple Inc. is on tap to report after the bell, followed by companies like Tesla Inc., Microsoft Corp. and Facebook Inc. on Wednesday.