Prediction Markets for Graded Cards
Bet up or down on what a card is actually worth. Every price is a completed Courtyard sale — the losing side pays the winners, and nothing settles on a number we invented.
How it works
No bookmaker, no order book, no house money. Two pools and a clock.
- 1
Pick a card
Every card runs back-to-back rounds. When one opens its price is recorded — what real copies of that card are selling for on Courtyard right now.
- 2
Bet up or down
Up means it finishes above where the round opened, down means below. Not how far it moves: a cent counts the same as fifty dollars.
- 3
Get paid
The unpopular side pays more, because fewer people split the same losing money. At expiry the losing pool pays the winners, straight to their wallets.
Every bet that lands moves both numbers. The busier a side gets the less it returns, because the same losing pool is shared further.
Common questions
Yes. Every price is built from completed sales on Courtyard, which holds around 400,000 graded cards as NFTs on Polygon. Nothing is simulated, and you can check any price against Courtyard or OpenSea yourself.
A single graded slab sells about once every eleven days — far too rare to price a market against. Courtyard holds many copies of the same card at the same grade, and together they sell many times a day; the busiest clears 84 sales daily. So a market is “this card at this grade”, which is what collectors quote anyway.
No. The pools decide the odds and nothing else. A wall of money on Up cannot push a card’s price up, because the price comes from what people paid for the card on a different marketplace entirely.
There is nothing to sell to. Money sits in one pool per side rather than in tradable shares, so there is no order book and no counterparty to buy you out. Offering an exit would need liquidity that does not exist.
Both pools are added together, the fee is taken, and the rest is split among the winning side in proportion to what each person staked. Hold a tenth of the winning pool and you receive a tenth of the total — so the number shown while betting is a live estimate, not a promise.
Everyone is refunded in full and no fee is charged. The same happens on a dead heat. With an empty pool there is nothing to win, so the round refunds rather than pretending somebody lost.
Your money cannot be trapped. Twenty-four hours after a round expires, anyone at all can force it to refund every bettor, with no fee taken. That is enforced by the contract rather than promised by us.
Pick a card. Pick a direction.
2,688 markets are open right now, on cards that really trade.
Open the markets
