What is a ticker ?

A ticker, a synonym for a stock symbol, is the short form of full security (asset). A ticker has a stream of quotes (AKA prices) attached to it, continuously updated throughout a trading session by the various exchanges.

For example, take ETH-BTC , if you have curl and jq installed, you can get a ticker from Kucoin with this command

curl -s https://api.kucoin.com/api/v1/market/orderbook/level1?symbol=ETH-BTC \
| jq .data

The result will look like this :

{
  "time": 1597187421265,
  "sequence": "1594340550066",
  "price": "0.033131",
  "size": "0.0013217",
  "bestBid": "0.03313",
  "bestBidSize": "2.1812529",
  "bestAsk": "0.033131",
  "bestAskSize": "2.8001025"
}

The first listed currency of a currency pair is called the base currency (ETH in our example), and the second currency is called the quote currency (BTC in our example). A price at 0.033131 means 1 Ether can be bought with 0.033131 Bitcoin.

These are the fields you can find on a ticker quote:

Field	Description
currencyPair	Currency pair
open	The opening price is the first trade price that was recorded during the day’s trading.
last	Last trade field is the price at which the last trade was executed.
bid	The bid price shown represents the highest price.
ask	The ask price shown represents the lowest price.
high	The day’s high price.
low	The day’s low price.
vwap	Volume-weighted average price (VWAP) is the ratio of the value traded to total volume traded over a particular time horizon (usually one day).
volume	Volume is the number of shares or contracts traded.
quoteVolume	Quote volume
bidSize	The bid size represents the quantity of a security that investors are willing to purchase at a specified bid price.
askSize	The ask size represents the quantity of a security that investors are willing to sell at a specified selling price.
timestamp	The moment at which the account information was retrieved.