Notable Wednesday Option Activity: TSRO, PRLB, SPSC

Looking at options trading activity among components of the Russell 3000 index, there is noteworthy activity today in Tesaro Inc (TSRO), where a total volume of 6,484 contracts has been traded thus far today, a contract volume which is representative of approximately 648,400 underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 64% of TSRO's average daily trading volume over the past month, of 1.0 million shares..