Stocks kept to a recent trading pattern, bobbing up and down in a fairly narrow range for a fourth consecutive session. The Nasdaq and S&P 500 added 0.1% each, while the NYSE composite was fractionally off. The small-cap S&P 600, a leader so far this year, tacked on 0.3%. The IBD 50 eased 0.1%. Volume rose across the board. Two technical tests await the market. The Nasdaq is butting up against resistance at 3,200, while the NYSE composite is