This script compares FTX BTC/PERP (BTC perpetual futures contract) price to Binance BTC/USDT spot and colors it red. It also plots Bitmex's BTC perpetual futures compared to Binance spot and colors it blue.
FTX = red Bitmex = blue
Now you can easily see that you can get a 1% discount on FTX perpetuals when it is tanking. This tells you that you can set your limit buy orders extra low if you like to catch crashes. Also, you can see what your average trader on each platform is willing to pay above or below the spot premium. In general you want to do the opposite of what the average trading is doing on these exchanges unless you're in the main bull or mania phase of the Bitcoin cycle.
If you want to use Bitstamp or your favorite exchange it can be changed in the settings. Let me know if you find any settings that work well for you.
Thanks !!