The Valley 50 significantly outperformed the broader market during the two-week period ended Sept. 25. Although the Dow Jones industrial average hit a record high during the period, it ended marginally lower while the Valley 50 gained a healthy 2.4 percent. The biggest gainer by far was Kythera Biopharmaceuticals Inc., which rose 75 percent after it announced successful Phase III results for its experimental fat-reducing drug. Among losers, Ceres Inc. fell 16 percent after yet another money-losing quarter followed by an analyst downgrade. In its quarterly filing the company said it expects growers in Brazil will order fewer of its crop seeds next season.