The Dow Jones Industrial Average jumped above 13,000 on Friday for the second time in a week.
In mid-afternoon trading, the best-known U.S. index was at 13,004, 20 points higher than where it began the day.
The Dow jumped above 13,000 on Tuesday before closing below that benchmark.
Rising markets would provide more good economic news for President Obama, who has seen his reelection chances improve with a strengthening economy.
Reports of increased consumer confidence boosted markets on Friday, and European stock markets were also higher as traders gained confidence in the economic bailout of Greece.
Updated at 2:55 p.m.: The Dow gave up its morning gains and fell into the red on Friday afternoon. At about 3 p.m., it was trading at 12,965 and was down 18 points on the day.