Implementing Limit Orders

Creating a maker order in the order book can be as depositing tokens at a specific price and redeeming this liquidity when a taker fills the order.

Maker vs. Liquidity Provider

• Maker: someone who wants to trade at a specific price. When you place your order, it's like you're saying, you want to sell this at exactly this price, no more, no less.

• Liquidity Provider: different from makers, LP contributes digital assets to a liquidity pool, enabling trading and other financial activities on the platform.

From the pool's perspective, both maker orders and liquidity provider contributions are equivalent to providing liquidity! Thus, order makers receive a liquidity supply token similar to the LP tokens for liquidity providers.

When you set your price as a maker, you receive a proof of deposit for the order (like a receipt) that proves you’ve put your tokens up for sale.

These receipts are in the form of NFTs stored in your digital wallet. They are unique certificates that can be claimed when a taker fills an order.

In an ideal order book exchange, orders are queued and filled on a first-come, first-served basis, with the possibility that orders might not be executed entirely at once.

ION Finance adopts a more efficient approach, taking into consideration the high cost of such operations in an on-chain environment. On ION, the execution condition for a limit order is that the whole liquidity of the bin has been reclaimed. Therefore, for a specific bin, the maker orders are either entirely executed or not executed at all. Instead of filling orders one by one, it waits until there's enough demand to fill several orders at once. It's like waiting for a group of buyers to come in and buy all the items in your stall in one go.