Top 10 Largest Purchases In Last 30 days Symbol Company Amount VMSI VENTANA MEDICAL SYSTEMS INC $2,380.34 Mil ENP ENCORE ENERGY PARTNERS L P $131.84 Mil SKYT SKYTERRA COMMUNICATIONS INC $83.22 Mil CPN CALPINE CORP $58.02 Mil ACF AMERICREDIT CORP $53.53 Mil BOBJ BUSINESS OBJECTS SA $52.38 Mil AMKR AMKOR TECHNOLOGY INC $33.74 Mil BKS BARNES & NOBLE INC $28.38 Mil SGEN SEATTLE GENETICS INC $26.84 Mil MMR MCMORAN EXPLORATION CO $23.38 Mil