Microsoft Investors May Eat Dividend and Have Price, Too

"While we expect MSFT to trade down on the ex-date, we believe it could fall by an amount less than $3," Bellini concluded in her note.

However, "how much the stock goes down depends how much it runs up going into the ex-dividend date," Bellini added in an interview last week. (Bellini has a buy rating on Microsoft and her firm has done banking with the company.)

So if Bellini is correct, investors should keep a close eye on the stock heading toward the Nov. 15 ex-dividend date to determine if the $3-a-share preholiday gift from Microsoft ends up being fully offset by a drop in price.