Noteworthy Tuesday Option Activity: MSFT, CAT, YHOO

Looking at options trading activity among components of the S&P 500 index, there is noteworthy activity today in Microsoft Corporation (NASD: MSFT), where a total volume of 686,055 contracts has been traded thus far today, a contract volume which is representative of approximately 68.6 million underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 234% of MSFT's average daily trading volume over the past month, of 29.3 million shares. Particula...