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.
//@version=2 study("Spread") sym1 = input(title="Symbol 1", type=symbol, defval="NK1!") sym2 = input(title="Symbol 2", type=symbol, defval="NL1!") diff=security(sym1,period, close)-security(sym2,period, close) plot(diff, color=red)