The Dow added more than 600 points after Federal Reserve governor Christopher Waller said he could support holding rates steady.

The rally spread across asset classes, with bonds also gaining as Treasury yields pulled back on expectations the Fed would pause its tightening cycle. Waller's remarks marked one of the more dovish signals from a sitting governor in recent months.

Traders interpreted the comments as increasing the probability of a rate hold at the next policy meeting, easing concerns that had weighed on markets earlier in the session. Equities extended gains into the close as volatility cooled.

The upbeat tone followed a stretch of uncertainty over the path of monetary policy, with investors closely parsing Fed officials' statements for clues on inflation and labor market conditions.