The Dow Jones industrial average rose 21.83 to 5,696.11.
Advancing issues led decliners by 1,268 to 1,147 on the New York Stock Exchange. NYSE volume totaled 347.23 million shares vs. 303.77 million yesterday.
Broader market measures also turned higher.
The NYSE composite index rose 0.84 to 353.65, and the Standard & Poor's 500-stock index rose 2.15 to 662.38. The Nasdaq composite advanced 8.33 to 1,128.86, and the American Stock Exchange's market value index rose 0.15 to 548.74.
There was no new economic data today to supplement last week's encouraging indications on inflation, and there was little corporate news to steer trading as investors focused on the start of this week's three-day auction of new U.S. Treasury debt.
The quarterly government refunding, fairly large at $39 billion, prompted the usual concerns over how well the Treasury market will absorb the new notes and bonds.
But the first phase, this afternoon's auction of $19 billion in three-year notes, failed to erode last week's gains in bond prices or send interest rates higher.
The yield on the 30-year Treasury bond - a key determinant of corporate and consumer borrowing costs - actually eased further, heartening stock investors hoping for lower operating costs and rising revenues.