Share markets have now erased much of their losses suffered in the wake of last week's UK vote to leave the EU.
The Dow Jones ended up 235.3 points, or 1.3%, at 17,929.99, and the S&P 500 gained 28.09 points, or 1.36%, to 2,098.86. The Nasdaq added 63.43 points, or 1.33%, to 4,842.67.
Hershey shares surged 16.8% on news that Mondelez had made a takeover bid.
"We're reversing the Brexit as it becomes evident that it was more of a political vote and decision than an economic decision," said Bucky Hellwig, senior vice president at BB&T Wealth Management.
Major gainers on the Dow included Boeing, Caterpillar, General Electric and IBM, all of which rose more than 2%.
Financial stocks were broadly higher after the Federal Reserve gave the green light to 31 of 33 banks to return capital to shareholders following stress tests. JPMorgan Chase rose 1.5%, Goldman Sachs 2.1%, and Wells Fargo 0.8%.
(Close): Wall Street enjoyed its third straight day of gains, with the major indexes closing up more than 1%.