The Philadelphia Eagles weren't Super Bowl underdogs for long.
The Kansas City Chiefs opened as slight favorites in the Super Bowl — 1.5-point favorites at BetMGM. A few minutes after the line was posted, it moved to Eagles -1.5. Then in a couple minutes it moved again, to Eagles -2.5. That's a quick reaction to the Eagles, who looked great in an NFC championship game win.
The over/under for the Super Bowl opened at 49.5 points.
Lines often move for the Super Bowl. There is a lot of money bet on the game, and there are two weeks for bettors to put their money down on either side.