Looking at options trading activity among components of the S&P 500 index, there is noteworthy activity today in Caesars Entertainment Inc (CZR), where a total volume of 33,169 contracts has been traded thus far today, a contract volume which is representative of approximately 3.3 million underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 77.3% of CZR's average daily trading volume over the past month, of 4.3 million shares..