Curtain
Curtain is a prediction market on crypto prices where nobody can see your bet. You choose a side and a stake on your own device, they are encrypted there, and the sealed math runs inside Arcium. Solana only ever stores ciphertext and the market totals.
Everyone sees the odds. Nobody sees you.
The problem it fixes
On a public prediction market, a position is readable the moment it lands. Wallet trackers and copy bots are sold as products. A large bettor moves the odds against themselves before they finish building a position, and anyone can follow their wallet into the next market.
On Curtain the board shows what everyone needs, the Yes and No pools, and nothing else. Your side and your stake stay sealed before settlement and after it.
What a market is
Version one runs binary price questions only, so settlement needs no judge:
| Field | Example | Where it lives |
|---|---|---|
| Price feed | Pyth SOL/USD | Market.feed_id |
| Strike | $110 | Market.strike, in the feed's own units |
| Deadline | Nov 1, 00:00 UTC | Market.expiry |
| Betting closes | a buffer before the deadline | Market.close_time |
The question is always the same shape: is the first Pyth print at or after the deadline at or above the strike? One market exists per feed, strike and deadline, because the market account address is derived from exactly those three values.
What happens to a bet
- You fund a sealed balance (a purse). The deposit is a normal token transfer, so its amount is public.
- You place a bet. Side and stake are encrypted on your device and sent as ciphertext.
- Arcium checks the bet against your sealed balance and drops a sealed ticket into the market's open batch.
- When a batch closes, Arcium adds its tickets up and posts only the new Yes and No totals. A batch is never added up with fewer than 5 different bettors in it.
- After the deadline, anyone submits the first Pyth print at or after it. That print decides the market.
- Every position is paid back into its owner's sealed balance, winners and losers alike.
- You withdraw to your wallet when you want. The withdrawal amount is public.
What Curtain is not
- Not the first private prediction market. Arcium's own Benchdot Markets has run confidential hiring markets on Solana mainnet since August 2026 with the same hidden-stake idea. Curtain's scope is general price markets.
- Not a market with a judge, a vote or an operator who picks the outcome.
Read next
- How it works: batches, epochs, the print rule and settlement.
- Security and trust: every trust assumption, including Arcium's permissioned phase.
- Economics: the parimutuel math and the fee.