Last week, for a brief period, there was some extreme options action in Cboe Global Markets (CBOE). The options traded 12x the normal volume, with 91% of the volume in calls. That many calls trading tends to be a bullish signal. In this case, the action was due to a rumor that CME had made a bid to purchase CBOE for $16 billion. CBOE shares spiked on the news, and many traders rushed to buy calls. However, CME soon denied the acquisition rumors and CBOE’s stock price plunged back to previous levels.