Floyd Mayweather is a decent sized favorite heading into this bout this Saturday with Conor McGregor, but it looks like a lot more cash is being bet on the UFC champ. So much so, bookies could be on the hook for some big time losses, if McGregor scores an upset on August 26th.

Back when talk of the boxing match really started to kick off, Mayweather was a huge favorite, as in the -2500 range, to win the fight. But, in recent weeks, those odds have changed dramatically, and now McGregor is an underdog in the +300 to +375 range.

Recently ESPN ran a story on this, which included quotes from several different oddsmakers, bookies and betting expers. Here is some of what they had to say:

“All I know is we’re less than a week away from making a lot of money or getting [clobbered],” William Hill director of trading Nick Bogdanovich said.

“Most of the people just ask to bet McGregor,” South Point oddsmaker Jimmy Vaccaro said. “They don’t even care what the price is.”

“This is like hanging -3 on the Super Bowl and seeing the line move to -8,” Jay Rood, vice president of MGM Resorts race and sports, told ESPN, revealing his company’s current ticket ratio of 25-1. Last month it was 50-1. “This could be the worst loss in the history of MGM Resorts.”

“Sharps are waiting to hit the Mayweather line when it bottoms out,” professional bettor and Yale economics major Rufus Peabody said. “There will be a lot of big-money bets on Mayweather. The question is how much of that will offset the public bets on McGregor.”

It’s a pretty fascinating development. Clearly there’s a lot of people who believe McGregor has a real shot at winning this thing, and this is in keeping with a narrative that’s developed in the last couple of weeks.

Originally, even in the MMA world, most observers argued that yes, McGregor has a puncher’s chance, but that Mayweather would likely dominate the fight. But, that opinion seems to have shifted to one that believes McGregor’s chances aren’t just limited to a lucky punch.

Mayweather – McGregor will be hosted by the T-Mobile Arena in Las Vegas, Nevada.