Trading
Above and Below share one order book. Orders are signed off-chain and matched fills settle on-chain.
One market, one order book
Above and Below are complementary outcomes. Buying Below at 40¢ is economically equivalent to selling Above at 60¢. A shared order book concentrates liquidity rather than splitting it between two independent books.
Order types
GTCGood ’til cancelled. The unfilled portion remains open until it fills, expires, or you cancel it.
IOCImmediate or cancel. Fills what is immediately available and cancels the remainder.
Post-onlyAdd liquidity only. The order is rejected if it would immediately match an existing order.
How fills settle
Depending on the matched positions, the hub contract can settle a fill in three ways:
- Transfer existing shares between traders.
- Create a matched Above/Below pair backed by collateral.
- Redeem a balanced pair back into ETH.
The contract chooses the valid mechanism while preserving the signed order terms.
Cancel an order
Cancel a single signed order on-chain, or invalidate all outstanding signatures by increasing your account nonce. A nonce is the version number attached to your orders.
Placing an order requires a wallet signature, not a transaction. On-chain cancellation and matched settlement require network gas.