Market can be set to BTCUSD, BTCEUR, BTCCHF, BTCGBP, BTC1!, BTC2!, SPX, and DTB3
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.