The Dow Jones industrial average surged more than 300 points on Thursday, building on gains from a day earlier after the Federal Reserve indicated that it was in no rush to raise interest rates as the economy strengthened.
Oracle led a rally in technology shares after the business software maker reported earnings that were better than expected.
Energy stocks lagged the market as the price of crude oil turned lower, erasing an early gain.
The Dow was up 303 points, or 1.8 percent, to 17,657 as of 1:38 p.m. Eastern.
The Standard & Poor's 500 gained 35 points, or 1.8 percent, to 2,048.
The Nasdaq climbed 87 points, or 1.9 percent, to 4,732.
Bond prices fell. The yield on the 10-year Treasury note rose to 2.21 percent.