Early Sunday morning, the New England Patriots remained a 4 1/2-point favorite at most sportsbooks in Nevada.
This despite at least four wagers of $1 million being placed on the Philadelphia Eagles, according to the Las Vegas Review-Journal.
Those wagers as well as another $3 million bet must have affected the line as with less than two hours before kickoff, William Hill had dropped the line New England -4 points.
The Review-Journal had reported that one bettor placed a $3 million wager on the Eagles on Jan. 24. MGM Resorts sports book director Jay Rood confirmed the $3 million bet, which he initially described as a "multimillion-dollar."
William Hill sports director Nick Bogdanovich told USA TODAY Sports "there is no explanation" to why so many large bets were coming in ahead of the game.
William Hill, which has operated in Nevada since 2012, had only taken one previous bet of $1 million or more before this week: a $1.2 million wager on Floyd Mayweather in his bout against Conor McGregor in August.
Sports books in Nevada are expected to take in a record $155 million worth of bets, shattering last year's total of $138.5 million.