One stock that Gibbons is particularly bearish on is Incyte (nasdaq: INCY - news - people), the first gene database company and one of Celera's rivals.
Among the largest underlying components of XBI, in trading today Pharmacyclics, Inc. ( NASD: PCYC) is up about 0.9%, Isis Pharmaceuticals, Inc. ( NASD: ISIS) is up about 3.6%, and Incyte Corporation ( NASD: INCY) is up by about 0.3%.