Looking at options trading activity among components of the Russell 3000 index, there is noteworthy activity today in Marinus Pharmaceuticals Inc (MRNS), where a total volume of 15,724 contracts has been traded thus far today, a contract volume which is representative of approximately 1.6 million underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 275% of MRNS's average daily trading volume over the past month, of 571,815 shares..