Looking at options trading activity among components of the S&P 500 index, there is noteworthy activity today in 3M Co (MMM), where a total volume of 43,384 contracts has been traded thus far today, a contract volume which is representative of approximately 4.3 million underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 112% of MMM's average daily trading volume over the past month, of 3.9 million shares..