Wall Street's main indexes opened higher on Wednesday as easing Treasury yields boosted megacaps, while investors awaited developments on a U.S. funding bill and inflation data this week to gauge the Federal Reserve's policy outlook.

The Dow Jones Industrial Average rose 63.93 points, or 0.19 percent, at the open to 33,682.81. The S&P 500 opened higher by 9.10 points, or 0.21 percent, at 4,282.63, while the Nasdaq Composite gained 51.75 points, or 0.40 percent, to 13,115.36 at the opening bell.