OPEN-SOURCE SCRIPT
Root mean squared error range (RMSER)
Similarly to Bollinger bands, the RMSER gives a support and resistance areas for the trading price. Unlike bollinger bands, which use standard deviation, this support and resistance is calculated with 2 * the root mean squared error away from the moving average. This works very well with indices, like 
SPX, and prices only fall outside the range during black swan events like the 2020 crash.
SPX, and prices only fall outside the range during black swan events like the 2020 crash. 
Open-source script
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 publications is governed by House rules. You can favorite it to use it on a chart.
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