Orders
Market, limit, reduce-only, and how the book matches them.
Order types
| Type | What it does |
|---|---|
| Market | Fills immediately against the book, up to your max slippage. The unfilled remainder rests as a marketable limit. |
| Limit | Rests in the book at your price. Fills when the market comes to it. |
| Reduce only | Can only reduce an existing position; never opens or flips one. |
Time in force
- GTC — good until cancelled.
- 1m / 1h / 1d — the order expires after that long if unfilled.
How matching works
The book is a central limit order book with price–time priority: the best price fills first, and among orders at the same price, the earliest. Matching happens in the sequencer in milliseconds and your fill appears in Positions the moment it happens.
What makes Lambdachain different is that the matching itself is later proven. Every block of trades comes with a zero-knowledge proof that fills happened at best-of-book, that cancelled orders were not filled, and that no order was reordered. The exchange cannot fill you at a worse price than the book showed; if it did, the block's proof would fail. See Proofs and Provers.
Cancelling
Cancel from Open Orders. A cancellation is a signed transaction like any other; once it is included, the order cannot fill, and the proof of that block attests to it.