How Much Is Yahoo Worth Without Alibaba? Not Much - Businessweek

A great ROI on Yahoo's 2005 $1B investment in Alibaba, in any case

"Here’s how to think about it: Yahoo has a stock market value of $34.1 billion, and owns a 24 percent stake in Alibaba. Estimates for the current value of Alibaba, which is planning an IPO, range between $75 billion and $125 billion. If it comes in at the low end of that range, Yahoo’s stake would be worth $18 billion, or just over half of Yahoo’s total market value. At the high end, Yahoo’s stake in Alibaba would be worth $30 billion—which would imply that the rest of Yahoo’s enterprise is worth as little as $4 billion, or 12 percent of its current value."

How Much Is Yahoo Worth Without Alibaba? Not Much - Businessweek