Order Book

CoinJar Exchange operates a central limit order book in each trading product. During continuous trading, orders are crossed as they are received by the trading engine, therefore the bid-ask spread between native orders is never zero or negative.

If an incoming order can be matched against an existing resting order or implied order, the incoming order is immediately filled at the price of the resting native order or implied order, and price improvement is possible. Resting orders are matched on a price-time priority basis.

Order book data are disseminated in 4 different formats:

Order Book Type	Dissemination Mode	Price Levels	Coalescing	Implied Price Levels
Level 1 aggregated order book	REST and WebSocket (`ticker:` channels)	Best Bid/Ask	Not coalesced^*	Best Bid/Ask
Level 2 aggregated order book (Recommended)	REST and WebSocket (`book:` channels)	Top 40	Every 100ms	Top 40
Level 3 aggregated order book	REST only	All	Every 100ms	Top 40
Full native order book	WebSocket only (`native_book:` channels)	All	Not coalesced	No

^* For ticker: channels only, new trades are not coalesced but best bid/ask data are refreshed every 100ms.

Orders at the same price levels are aggregated with only the total size displayed.