The stock market made a rebound of sorts in the two-week period ended Feb. 19. The Dow Jones Industrial index ended with a 3.9 percent gain, once again climbing above 16,000. The Valley 50 fared even better with an increase of 4.1 percent. Among the top gainers was Qualstar Corp., which rose 22 percent after reporting a significant narrowing of its net loss during the fourth quarter. Biotech firm MannKind Corp. gained 16 percent after it made available a new set of share options. Internet advertising firm ReachLocal Inc. had the biggest drop at 17 percent. The Woodland Hills company’s fourth-quarter filing reported a net loss, while analysts had forecast a profit.