Americans are expected to bet about $4.76 billion on Super Bowl 52 between the New England Patriots and Philadelphia Eagles, according to The American Gaming Association.
More than 97% of the total wagers will be bet illegally across the United States, which includes local bookmakers and various offshore sportsbooks.
"Thanks to the failed federal ban on sports betting, Americans are sending billions of their hard-earned dollars to corner bookies, shady offshore operators and other criminal enterprises," Geoff Freeman, president and CEO of the American Gaming Association, said in a statement. "The big question we're asking: Is 2018 finally the year when governments, sporting bodies and the gaming industry work together to put the illegal sports betting market out of business?"
The AGA says only three percent of all total Super Bowl bets are expected to be legally wagered in Nevada sportsbooks.
Nevada is the only state in the union that is exempt from a federal ban on sports better.
Last month, the United States Supreme Court heard the case about sports betting in Christie v. NCAA, which challenges the Professional and Amateur Sports Protection Act of 1992. A ruling on the case is expected later this year.
The Patriots are currently 4.5–point favorites over the Eagles in Super Bowl.