When you post a listing you set a minimum and maximum amount per trade. Other users can take the listing in parts: each one trades for whatever amount they want within that range, until the listing runs out.
How it works
- The original listing is the "parent"; every trade someone takes is a "child".
- The listing's available amount decreases atomically with every trade, so it can never be oversold.
- The funds for each trade stay reserved until it's completed or cancelled.
It's the same model you know from the big exchanges' P2P: you post once and several people buy/sell from you little by little.