Bovada.lv currently has Mickey Gall a -300 favorite to CM Punk (+265) in their opening betting lines for the September 10, 2016 fight at UFC 203.
The same site has Brock Lesnar a +130 underdog to -160 Mark Hunt for their fight at UFC 200 on July 9, 2016 in Lesnar's return to the octagon.
In the broad scheme of things, the odds don’t mean a lot. We’ve heard the oddsmakers are convinced Lesnar will lose to Hunt but at the end of the day, the fight still has to happen. Punk being a heavy underdog is less of a surprise considering UFC 203 will be his first professional fight.