how can i get data from GDAX Bitfinex using API and show like bottom
They are just using websocket to connect to the exchange and then outputting the lives trades to the page by appending it to an element. 

Here's a simple example using bitfinex:

&lt;html&gt;
&lt;div id="btc"&gt;&lt;/div&gt;
&lt;script&gt;
var ws = new WebSocket("wss://api2.bitfinex.com:3000/ws");
ws.onopen = function(){
  ws.send(JSON.stringify({"event":"subscribe", "channel":"ticker", "pair":"BTCUSD"}))
};
ws.onmessage = function(msg){
  var response = JSON.parse(msg.data);
  var hb = response[1];
  if(hb != "hb"){
    document.getElementById("btc").innerHTML = "$" + response[7];
  }
};
&lt;/script&gt;
&lt;/html&gt;