Limit Orders

Core Concept of Limit Orders

A limit order allows you to specify the maximum price you're willing to pay (for BUY orders) or the minimum price you're willing to accept (for SELL orders). These orders do not execute immediately unless there's a matching counterparty. Instead, they’re added to the order book and wait for a match.

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Matching Logic

• We immediately scan the order book for existing limit orders that can fully or partially match your order.

• Matching rules:

  • BUY YES will match with SELL YES at prices ≤ your limit.

  • BUY NO will match with SELL NO at prices ≤ your limit.

  • SELL YES will match with BUY YES at prices ≥ your ask.

  • SELL NO will match with BUY NO at prices ≥ your ask.

• If matches are found:

  • We create matched trades.

  • We trigger on-chain settlement to escrow collateral and mint outcome tokens.

• Partial Fills & Fallbacks

  • If your order can only be partially matched, the remainder is kept as a new open limit order.

  • If no matches are found, your entire order is stored in the limit order book.

Maker-Taker Priority

Mettle Market uses maker-taker price priority for all matches — including standard and cross-side matches:

• The maker is the trader whose order was already resting in the order book.

• The taker is the trader who submits a new order that triggers the match.

• The trade executes at the maker’s price, not the taker’s.

This ensures:

• Makers receive their requested price

• Takers never pay more (or receive less) than they agreed to

• Price-time fairness across all trades

Even in cross-side matching (e.g. BUY YES vs. BUY NO), the first order is treated as the maker, and the match executes at that price for both parties.