ticker
channel describes some properties of the current state of the order book (in particular it has some pieces of information about the last match) and a message is sent on this channel whenever a (cascading) match happens.
This is a message I just got from the ticker
channel (I removed some entries for brevity):
{
'type': 'ticker',
'product_id': 'BTC-EUR',
'price': '41353.04',
'best_bid': '41343.73',
'best_ask': '41353.04',
'side': 'buy',
'time': '2021-10-02T20:34:01.789371Z',
'trade_id': 50907907,
'last_size': '0.0037041',
...
}
In particular, here we see that the current highest open buy order is 41343.73 and the lowest open sell order is 41353.04. I can see that the taker side is "buy" (comment from the docs: "side": "buy", // Taker side
). It makes sense that the price (I assume it's the price of the last match) is at the lowest_sell order ('price': '41353.04' which probably wasn't filled 100% so it remains at this level).
Here's a matching :) match message from the matches
channel which describe matches, and not the current state of the order book.
{
'type': 'match',
'trade_id': 50907907,
'maker_order_id': 'bc002935-a5ce-484c-b3e5-bc353138fe65',
'taker_order_id': 'e575a531-21a8-447d-9801-6c79b136dc0f',
'side': 'sell',
'size': '0.0037041',
'price': '41353.04',
'product_id': 'BTC-EUR',
'time': '2021-10-02T20:34:01.789371Z'
}
Here the side is "sell", from the docs of the "match" message: The side field indicates the maker order side.
.