3 of those as trend filters (EMA17, EMA34 and EMA40)
And the EMA4 as a buy and sell signal.
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 a publication is governed by House Rules.
You can favorite it to use it on a chart.
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