Yahoo (YHOO, news, chart, volatility) calls are active. 28,000 contracts have traded, more than four times the number of put options. The stock is up 43 cents to $13.18 and hit session highs of $13.49 about 90 minutes ago. The jump in call volume and spike in the shares coincided with a Bloomberg report that said Bernstein expects the Google (GOOG)-Yahoo deal to falter and that Microsoft (MSFT) will step in with a $20 per share bid for Yahoo some time in 2009.