Hi, I noticed that sometimes the call options volume regarding ITM calls increases substantially in the day before the ex-dividend date. For example, on November 14, 2011, the day before MSFT's ex-date, the volume for the January 2012 15 call was 396,000 contracts. In general, when the regular daily volume is a few hundreds contract the volume in the day before the ex-date regarding specific ITM strikes can increase substantially to thousands, ten thousands, or even hundreds thousands (as was the case regarding MSFT). Also, on the ex-date itself the open interest usually does not increase by such huge amounts which may indicate that the option contracts that were heavily traded on the day before the ex-date were either closed out in the market or exercised/assigned. I am sure there should be a good reason for such an increase in volume -- it does not seem like a usual trading activity by retail customers or market makers. I would be happy to read any ideas. Thanks!