Stocks closed out the last trading day of September with a bang, but still suffered big losses for the month and quarter. The Nasdaq bolted 2.3%, thanks to strength in data storage, biotech and chips. The S&P 500 rallied 1.9% and the Dow Jones industrial average gained 1.5%. According to preliminary data, volume ended lower across the board in the stock market today. For the month, the Nasdaq slumped 3.3% and the S&P 500 lost 2.7%.