Mayweather opened up at -600 on betting site Bovada, which means that a person would need to bet $600 to make $100 on a Mayweather victory.
McGregor currently sits at +400, which means a $100 bet on the Irish-born fighter would pay out $400.
A very interesting option is what specific round the fight will be won in. Bovada believes that the most likely option for that is Mayweather winning in rounds four through eight, and has the line set at +1400.
The riskiest option for those really looking to cash in would be betting at +5000 that McGregor wins in round 11.
The lines will certainly shift all the way up until the fight begins.