Like the LVH, some books in Las Vegas opened the game at 4.5 points, while others put their number up at 5. Most of the major Las Vegas sports books were at 4.5 points, with a few listing the 49ers at 4 points Sunday night.
The over/under, where bettors can wager on whether the two teams will combine for more or less points than the posted number, was at 49 points at most books.
Point spreads fluctuate on games, especially the most heavily bet ones, according to how much oddsmakers take on each team. A big bet on one team can sometimes send a line moving a half point one way or another, though most movement normally takes place in the days just before the game.
Nevada oddsmakers also post hundreds of proposition bets on the game, everything from who will win the coin flip to which quarterback will have more passing yards. Those bets aren't expected to be posted fully until later in the week.
Vaccaro said the proximity of the 49ers to Nevada should boost betting on the game.
Casinos have lost once only once on the Super Bowl the last 10 years, in 2008 when bettors gambled $92 million and casinos lost $2.57 million as the Giants beat New England, 17-14.