) announced that the two companies will not merge any time soon. "For the foreseeable future, we don't see the need for large-scale M&A," CME CEO Craig Donohue said in an interview with Reuters on Thursday. "As we are thinking about the next five years, our focus is really on driving growth in our core business. That's really the next phase for us." William Brodsky, CEO of CBOE's parent company, echoed Donohue's comments earlier this week. "I'd rather build this company organically, in things that I understand and can do very well with, than just get involved in some transaction just to say we've done a transaction," Brodsky told Reuters in an interview on Monday. "I think we have everything in place where we can operate as we are for an indefinite period." Both companies are derivatives exchange operators. Shares of CME are down more than 2.3% today, to $279.10. CBOE is down 0.5%, to $26.54.