The stock market tried for a rebound but ended with mixed results after a back-and-forth session Tuesday. The Nasdaq ended down 0.6% after being up more than 1% intraday. It fell for a sixth straight session, matching its late-August losing streak. Biotechs were again an area of weakness, after an initial bounce. IBD’s Medical-Biomed/Biotech industry group lost 2.8%. Software stocks also came under pressure. The S&P 500 rose 0.1%.