Stock indexes posted small losses in quiet volume Thursday, curbing any zeal that might have been blooming among the bulls. The Nasdaq stepped back 0.4%, while the S&P 500 shuffled down less than 0.1%. The small-cap S&P 600 dropped 1%. The IBD 50 shed 0.4%. Volume fell across the board. After big gains in three of the previous five sessions, the stock market Thursday was ready for a reality check.