Looking at options trading activity among components of the S&P 500 index, there is noteworthy activity today in Walgreens Boots Alliance Inc (WBA), where a total volume of 180,446 contracts has been traded thus far today, a contract volume which is representative of approximately 18.0 million underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 65.6% of WBA's average daily trading volume over the past month, of 27.5 million shares..