That system doesn't necessarily work all the time.Same charts, just a different trading system.
Buy funds when the 14-day RSI becomes more than the 20-day RSI.
Sell funds when the 14-day RSI becomes less than the 20-day RSI.
I'm back to:
Buy funds Buy funds when the 14-day RSI and 20-day RSI total more than 100.
Sell funds when the 14-day RSI and 20-day RSI total less than 100.
As for using the RSI for overbought/oversold, what period of RSI do you use?, how much do you call it?, 70/30?, 80/20?, 65/35? Does the same thing work every time for every fund?
Any strategy will have some losses. Typically, successful traders have many small losses.