NEW YORK – 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.