Looking at options trading activity among components of the S&P 500 index, there is noteworthy activity today in Parker Hannifin Corp (PH), where a total volume of 4,084 contracts has been traded thus far today, a contract volume which is representative of approximately 408,400 underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 52.7% of PH's average daily trading volume over the past month, of 774,870 shares..