Stocks ended narrowly mixed and took a breather Monday after rising for the past four weeks. The Nasdaq squeezed out an 0.1% gain, despite a 3% drop in index heavyweight Apple (AAPL). Chips stocks were also weak. The Philadelphia semiconductor index slumped 2%. But Internet content stocks were strong Monday. The benchmark S&P 500 fell 0.2% after being down as much as 0.4% earlier in the day.