The Dow Jones industrial average made up for the distance it lagged behind other indexes yesterday, but the rest of the market mostly treaded water today.

The Dow climbed 43.5 points to 10,557.39 while the Nasdaq Stock Market composite index advanced by less than a point to 2,144.11 and the Standard & Poor's 500 stock index gained a single point to 1,223.29.

The S&P 500 is bumping up against an invisible barrier, for some reason unable to climb past 1,225 -- the high it reached last spring. Technical traders, who chart the ups and downs of the market, offer arcane mathematical theories about why stock indexes sometimes hit walls like this.

Those theories may just be Wall Street witchcraft, but the stock market soothsayers insist the future of stock prices depends on whether the S&P breaks through whatever it is that is holding it back.

Today stocks got some boost from a surprise improvement in the nation's trade deficit, which fell 2.8 percent last month because U.S. companies exported record amounts of goods. Traders were reluctant to make too much of the improvement in the trade gap, however, because analysts warned it was probably a one-month temporary phenomena.

Investors who have been counting on sold corporate profits to boost stock prices got some encouragement today from Abbott Laboratories and Harley-Davidson, the motorcycle company.

And after the bell, Apple Computer delivered more good news: sales up 75 percent to 43.5 billon, profits multiplied from $61 million (8 cents a share) to $320 million (37 cents).