Difference between "trade" and "orderBookUpdate"

[Henriii]

Hi,

First I want to thank you for creating this project, so far it works really good for me!

Now to my question: Could you explain the difference between "trade" and "orderBookUpdates" events? From my understanding a trade would also trigger an orderBookUpdate, since it changes the orderbook on the exchange?!

Do I need to handle "trade" events when I want to keep a sync of an orderbook?

[aloysius-pgast]

Hi. Thanks for your feedback. Regarding the events :

• trades event will be emitted whenever some orders are fulfilled on exchange (ie: when orders are matched).
• orderBook & orderBookUpdate events are only related to new orders being submitted to the order book or removed from the order book

If you're interested in keeping your order book in sync, handling orderBook & orderBookUpdate is enough, you don't need to handle trades event (unless you also want to keep track of the orders which have been matched).

When an order is matched, any exchange will emit both events :

• trades : since an order was fulfilled
• orderBookUpdate : since at least two entries in the order book have changed (because a buy order matched a sell order)

[Henriii]

Thank you! Much appreciated.