Stocks are mixed in midday trading as investors weighed the impact of President Barack Obama's budget proposal for the next fiscal year.

Obama unveiled a $3.73 trillion budget Monday that includes a five-year freeze on many domestic spending programs. Republicans and Democrats have argued recently over whether deep spending cuts will slow the economy's recovery.

Wal-Mart Stores Inc. dropped 1.4 percent after analysts at JPMorgan downgraded the company. Wal-Mart was the weakest stock among the 30 that make up the Dow Jones industrial average.

The Dow fell 18 points, or 0.1 percent, to 12,255. The S&P 500 rose less than a point to 1,329. The Nasdaq composite gained 7 points, or 0.3 percent, to 2,816.