Best-selling mystery writer Mary Higgins Clark has purchased a seat at the Chicago Board Options Exchange(CBOE), according to Crain's. Clark is married to futures industry titan and former Merrill Lynch CEO John Conheeney. Personally, I devoured Clark's novels in junior high, and I wasn't alone, as Clark reportedly sold between 80 and 100 million copies in the U.S. Bloomberg reports that Clark paid $2.95 million for her seat. For CBOE itself, the latest mystery is what will happen in the wake of its much-delayed and long-anticipated IPO announcement a few weeks ago. Before the IPO announcement, CBOE and CME Group entered into a licensing agreement related to CBOE’s volatility franchise, leading to speculation about a larger deal between the two Chicago exchange operators.