The week’s biggest gainer was Westwood-based Puma Biotechnologies Inc., which was up 46 percent to end at $50.40. Aerospace manufacturer Ducommun Inc in Carson was also up big, gaining 36 percent to close at $25.48. The week’s biggest laggard was Pasadena-based Arrowhead Pharmaceuticals Inc., which lost 24 percent to close at $4.18.