U.S. stocks rose for the first time since Britain voted to leave the European Union, with the S&P 500 Index surging the most in nearly four months, amid optimism that policy makers are committed to limit the fallout from the U.K.'s exit.

Tuesday's turnaround gathered pace late in the day, with the Dow Jones Industrial Average adding more than 260 points. Banks had the strongest rally in six weeks, after their worst two sessions in almost five years. Facebook Inc., Apple Inc. and Microsoft Corp rose at least 1.6 percent to boost the technology group, while energy producers climbed the most in 2 1/2 months as crude prices jumped.

The U.K.'s decision last week triggered a rush toward safe havens as global equities lost about $3.6 trillion in market value and the S&P 500 tumbled 5.3 percent to erase its 2016 advance. The CBOE Volatility Index tumbled for a second day, though the measure of market turbulence known as the VIX is still on the way to its biggest monthly climb since a record jump last August.

European Central Bank President Mario Draghi added to speculation of a more coordinated effort by policy makers to mitigate the Brexit repercussions, calling for global policy alignment in a speech at the ECB Forum in Sintra, Portugal. Draghi said there is a "common responsibility" to address the world's economic weaknesses. U.K. Prime Minister David Cameron will face EU leaders at a dinner in Brussels on Tuesday, after both the Bank of England and European Central Bank pledged to increase liquidity.

EU leaders are gathering for a two-day European Council summit to discuss Britain's exit. Germany, France and Italy prodded the U.K. government to start the process, saying they want to move forward and limit market risks. Britain's Chancellor of the Exchequer George Osborne sought to reassure investors on Monday, saying that contingency plans were in place to shore up the economy amid ongoing volatility, but that Brexit won't be "plain sailing" -- something that Cameron reiterated in Parliament.

Aside from the Brexit drama, a report today showed the U.S. economy expanded more than previously projected in the first quarter as improved performance in trade and business investment more than made up for weaker consumer spending. Separate data showed consumer confidence rose to the highest since October as Americans became somewhat more optimistic about the economy.