US stocks clung to gains Thursday afternoon and the dollar fell after the Federal Reserve announced it would keep its key interest rate at zero.

Stocks briefly went negative about five minutes after the 1800 GMT Fed statement, but soon moved back into positive territory in choppy trade.

Near 1825 GMT, the Dow Jones Industrial Average was at 16,770.80, up 30.85 points (0.18 percent).

The broad-based S&P 500 rose 6.99 (0.35 percent) to 2,002.30, while the tech-rich Nasdaq Composite Index gained 25.62 (0.52 percent) at 4,914.86.

The dollar retreated against other major currencies, compared with its levels before the Federal Open Market Committee statement was released. 

The euro was at $1.1395, up from $1.1330 before the FOMC statement. The dollar fell to 120.37 yen from 120.85.

Bond prices rose. The yield on the 10-year US Treasury fell to 2.23 percent from 2.30 percent Wednesday, while the 30-year dropped to 3.04 percent from 3.08 percent. Bond prices and yields move inversely.