Looking at options trading activity among components of the S&P 500 index, there is noteworthy activity today in ServiceNow Inc (NOW), where a total volume of 4,426 contracts has been traded thus far today, a contract volume which is representative of approximately 442,600 underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 48.4% of NOW's average daily trading volume over the past month, of 913,790 shares..