Moneyline
A bet on which side simply wins the event, with no point spread or handicap involved — you just pick the winner.
Definition
The moneyline is the market for the straight outcome of a match, quoted in American odds. Favourites carry negative odds showing the stake needed to win 100 units (e.g. -150 means risk 150 to win 100), while underdogs carry positive odds showing the profit on a 100-unit stake (e.g. +130 means a 100 stake wins 130). Most US markets (baseball, basketball, football, hockey) are two-way because ties are rare or broken; association football and some other sports use a three-way moneyline that adds the draw as a separate selection. The operator's margin is embedded in the prices, so the implied probabilities of all outcomes sum to more than 100%.
Worked example
An NFL game is priced Chiefs -150, Broncos +130. Backing the Chiefs means staking 150 to win 100 (a 250 return); backing the Broncos means staking 100 to win 130 (a 230 return). Converting to implied probability: -150 implies 150/250 = 60.0% and +130 implies 100/230 = 43.5%. Those sum to 103.5%, so roughly 3.5% is the operator's built-in margin (overround) rather than a true reflection of the teams' chances.
Why it matters
The moneyline is the clearest expression of a market's view on who wins, and learning to convert American odds into implied probability — then netting out the operator's margin — is a foundational skill for reading any priced market. For traders and analysts, moneyline prices are the reference point from which spreads, totals and derivative markets are derived, so misreading them propagates errors across a whole book. For anyone studying odds, it also makes the house edge visible: the outcome probabilities always add up to more than 100%.
Related
Note: Concept is stable, but terminology and format vary: "moneyline" and American odds are US conventions, whereas the same bet is usually called the win, match-odds or 1X2 market and quoted in decimal or fractional odds elsewhere. Whether a market is two-way or three-way depends on the sport and how ties are handled, and exact prices, margins and tie/push rules vary by operator and jurisdiction.