Wall Street stocks finished mostly lower on Wednesday, concluding a volatile session after the Federal Reserve kept interest rates flat and signaled rate hikes were not probable.

Major equities had shot higher after Fed Chair Jerome Powell called further rate hikes unlikely, but those gains largely faded in the final moments of the session.

The Dow Jones Industrial Average ended at 37,903, up 0.2 percent from Tuesday, but down almost 450 points from its session peak.

The broad-based S&P 500 declined 0.3 percent to 5,018, while the tech-rich Nasdaq Composite Index lost 0.3 percent at 15,605. (AFP)