Looking at options trading activity among components of the S&P 500 index, there is noteworthy activity today in Cintas Corporation (CTAS), where a total volume of 2,432 contracts has been traded thus far today, a contract volume which is representative of approximately 243,200 underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 50.9% of CTAS's average daily trading volume over the past month, of 478,125 shares..