Looking at options trading activity among components of the S&P 500 index, there is noteworthy activity today in NVIDIA Corp (NVDA), where a total volume of 1.9 million contracts has been traded thus far today, a contract volume which is representative of approximately 187.5 million underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 84% of NVDA's average daily trading volume over the past month, of 223.1 million shares..