The Dow Jones industrial average climbed as much as 210 points during morning trading as traders returned from the Memorial Day holiday.
U.S. government bond prices fell as investors moved money out of safe assets and into riskier ones. The yield on the 10-year Treasury note climbed to its highest level in more than a year.
The Dow was up 163 points at 15,466 as of noon Eastern Daylight Time Tuesday, a gain of 1 per cent.
The Standard & Poor's 500 index was up 17 points at 1,666, or 1.1 per cent.
The Nasdaq composite was up 43 points at 3,502, a gain of 1.3 per cent.