Yahoo: 20 years of hits and flops

In one of its most prescient -- or luckiest -- acquisitions, Yahoo paid $1 billion for a 40% stake in Alibaba in 2005.

That stake is now worth about $40 billion, and Yahoo decided to spin it off into a separate company following Alibaba's (BABA) monster IPO. That spinoff is now equal to Yahoo's total market valuation.