💡How it Works

Oso is a binary parimutuel prediction market, allowing users to guess YES or NO, WIN or LOSS, A or B, etc on critical questions throughout the world of crypto, finance, sports, and culture.

Markets operate on a parimutuel model, meaning the odds are not fixed until all bets are in. Since winners simply win what the losers bet, minus fees, the final odds can't be determined until betting is closed.

There are three stages for each OSO market:

1. OPEN - Bets are accepted, odds shift based on the proportion of bets in each option.

2. LOCKED - No more bets are accepted, and the odds have been settled. Now we just wait for the result....

3. SETTLED - The results are in, the oracle has reported, and the market is complete. Winners can collect their reward through the market page on the OSO site, or everyone can reclaim their initial in the event of a push.

Pari-mutuel: A form of betting market in which the odds are not determined until the market closes, as the payouts are based on the total bets in the pool.

To put it another way, there's no 'house,' it's PVP, so you win what the other side loses, based on your share of the winning pool.

If you have 10% of the winning side, let's say 1 ETH out of 10 total ETH bet by the winners, you win 10% of the loser's bets, minus market maker fees. If the losers bet 5 ETH in total, you'd win .5 ETH before fees. If the losers bet 50 ETH in total, you'd win 5 ETH before fees.

See Our Rules for Oso's current fee schedule.