Notable Friday Option Activity: GRUB, COOL, BIIB

Looking at options trading activity among components of the Russell 3000 index, there is noteworthy activity today in GrubHub Inc (GRUB), where a total volume of 5,945 contracts has been traded thus far today, a contract volume which is representative of approximately 594,500 underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 60.3% of GRUB's average daily trading volume over the past month, of 985,490 shares..