> If you break it down, the Yahoo Alibaba + Yahoo Japan stake + Yahoo's final selling price equals Microsoft's $45/share offer

Actually, if mayer didn't sell a huge chunk of alibaba stake, the BABA stake by itself would be worth 120% of microsoft's bid.

YHOO owned 25% of alibaba. Alibaba is worth $400 B today. Microsoft's offer was $45 billion for YHOO.