Stocks gave up most of an early surge on Wall Street and briefly dipped into the red a day after the market’s biggest drop since 2008.

The Dow had been up 945 points in the early going, dipped into the red and then went higher again shortly after noon.

Markets bumped up after Vice President Mike Pence said the nation’s big health insurers would cover co-pays for coronavirus testing. Investors are likely to see more big swings until the number of infections from the new coronavirus decelerate, and they also want a big, coordinated response from governments and central banks.

U.S. stocks, oil and other financial markets around the world clawed back some of their historic plunge from a day before this morning, amid hopes that the U.S. and other governments around the world will pump in more aid for a virus-weakened global economy.

Investors welcomed Tuesday’s reprieve but weren’t pretending that this is the end to the market’s huge swings, which took the S&P 500 on Monday to its worst day since the 2008 financial crisis. Even Tuesday’s big morning gains were tentative: After spurting to a gain of 3.7 percent, the S&P 500 quickly gave up more than half of it.

Dizzying swings have been relentless in markets the last few weeks. Stocks had a couple days last week where they rose more than 4 percent, only for the bottom to give out again.