Looking at options trading activity among components of the Russell 3000 index, there is noteworthy activity today in Glaukos Corp (GKOS), where a total volume of 3,913 contracts has been traded thus far today, a contract volume which is representative of approximately 391,300 underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 88.1% of GKOS's average daily trading volume over the past month, of 444,040 shares..