Conor McGregor vs. Floyd Mayweather Betting Odds Drop to Under 4-1 for Notorious

Conor McGregor opened as a +950 underdog (wager $100 to win $950) for his megafight against Floyd Mayweather Jr. when buzz started to circulate last November that the two could duke it out in a boxing match, but his odds have shifted in a positive direction rapidly since the bout was officially announced in June.

As of Tuesday, McGregor is listed as a +375 underdog, with Money a -550 favorite (wager $550 to win $100).

Additionally, bettors can get McGregor at +450 if they think he will win by knockout or +1000 if they think he can outlast Mayweather via decision.

Money, meanwhile, is -140 to win by knockout—a result he hasn't secured since 2011 against Victor Ortiz—and +250 to win by decision.

On Tuesday, Bovada sportsbook manager Kevin Bradley told Yahoo Sports' Kevin Iole there has been a heavy volume of wagers on the fight, and the books could hemorrhage cash if the UFC lightweight champion pulls off a stunning knockout upset.

"One thing is for sure, though, we will need Mayweather huge," Bradley said. "A McGregor early round KO as he promised would be a potential disaster and is partly a reason we are giving a great price on Mayweather at the moment."

Bradley also said he thinks there's a good chance betting for the fight will outpace the Super Bowl after the fighters' international press tour generated additional interest in the unprecedented clash.

"We knew this fight would be big, potentially even bigger than the Super Bowl, but now we are almost certain it will be," he said.

Odds courtesy of OddsShark.