A sportsbook is a gambling establishment that accepts bets on various sporting events. They are commonly found online and in Las Vegas. A sportsbook can also be referred to as a bookmaker or a sports betting exchange. A legal sportsbook must be licensed and comply with state regulations. The capital required to start one varies depending on the size of the market, licensing costs, and monetary guarantees required by the government. It is recommended that a sportsbook should have at least $10,000 in reserve, which can be used for operating expenses and marketing strategies.
Sportsbooks earn revenue by taking bets on both sides of an event, paying winning bettors and collecting commission, or “vigorish,” on losing bets. The amount of vigorish collected is typically 10% but may be higher or lower in some cases.
Betting volume at a sportsbook varies throughout the year and spikes when certain sports are in season. This is because bettors have more interest in certain games and increase the money they wager on them. Moreover, sports that do not follow a set schedule, like boxing, create seasonal peaks of activity for sportsbooks.
Sportsbooks can change their odds at any time, and the goal is to get as balanced action as possible on each side. This is because if one side of a bet wins more often than another, the sportsbook will lose money. This is why oddsmakers move the lines to encourage bettors to place bets on both sides of a game or contest.