The data you're loading is a JSON formatted array so loadStrings won't be very useful in this case.
You should be using loadJSONArray() and JSONObject to parse the data from each entry in the array you're loading.
Here's a basic sample using just the amount
values:
void setup(){
JSONArray data = loadJSONArray("https://btc-e.com/api/2/btc_usd/trades");//load the data
for (int i = 0; i < data.size(); i++) {//traverse the data
JSONObject entry = data.getJSONObject(i); //get each entry in the list/array
//parse the values
float amount = entry.getFloat("amount");
int price = entry.getInt("price");
String item = entry.getString("item");
String pc = entry.getString("price_currency");
int tid = entry.getInt("tid");
int date = entry.getInt("date");
String tt = entry.getString("trade_type");
//do something with the data
float x = (float)i/data.size() * width;
float y = 100 - (amount * 20);
line(x,height,x,y);
}
}
And here's the output:
Another note: in your code, you use loadStrings in the draw() loop which means you're loading the same data over and over again multiple times(about 60 by default) per second which is not a good idea. You should load the data once, have it available in a top level variable and reuse the loaded data in a draw() loop when you need it.
Also, if you're loading external data you might need to sign the applet. Check out this guide. I've used the same guide to post this applet.