Michael Selig, chairman of the Commodity Futures Trading Commission, says political contracts on federally regulated exchanges should be tied to specific events and not open-ended. The risk is that these bets could become an ``assassination market,'' he tells Bloomberg's Tim Stenovec in Boca Raton, Florida. -------- More on Bloomberg Television and Markets Like this video? Subscribe and turn on notifications so you don't miss any videos from Bloomberg Markets & Finance: https://tinyurl.com/