Looking at options trading activity among components of the S&P 500 index, there is noteworthy activity today in Palo Alto Networks, Inc (PANW), where a total volume of 77,158 contracts has been traded thus far today, a contract volume which is representative of approximately 7.7 million underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 359.1% of PANW's average daily trading volume over the past month, of 2.1 million shares..