"It seems to have captured the betting public's imagination like we have never seen before. Not just in terms of boxing events but sporting events," said a representative of Betfair, Barry Orr in a report quoted by The Daily Mail website.
Although Floyd Mayweather is the favourite having gone unbeaten in 49 professional contests across 21 years, Conor McGregor is the popular choice among gamblers, though the big-money bets tend to be placed on Mayweather.
In the hours after it was announced the two fighters would wear 8oz gloves in Las Vegas, Betfair alone took £1.5m in bets.
"Industry wide, it's one of the biggest sporting events that's going to be bet on for a long, long time. I think it's going to break all records," Orr assured.
The fight will take place this Saturday at the T-Mobile Arena in Las Vegas. According to McGregor, the event will surpass the 4.6million pay-per-view buys garnered by Mayweather's 2015 showdown with Manny Pacquiao.