Does Yahoo! even have $2 billion to spend on something? I don't remember them buying anything above a few million in a long time and Groupon doesn't scream 'turning around the fortunes of the company' to me
Cash and Short term investments stood at 2.75B as of June 30, as the article says their market cap is 19.5B. I would guess it wouldn't be an all cash purchase but likely a combination of cash and stock.