Keep in mind I use the RSI 21 because it rarely goes below the oversold 30 line or over the overbought 70 line. So when it does it is significant. The standard RSI 14 will go below 30 and above 70 much faster and earlier and can get you 'reacting' with a trade far too soon. But each market has its own volatility and beta so it's always best to look back with the RSI at whatever level you set it at and see how often it tags these important oversold and overbought levels plus lines up with price lows and highs. This will give you a better idea of how prices react at those RSI levels. There are markets that have low volatility and almost never see the RSI 21 tag these signal levels. So you can use the RSI 14 or even a lower setting at these price selloff lows and price rally highs when reversing back. I prefer the RSI 21 but for shorter term trades the RSI 10 works very well for swing trading. Some use the RSI 7 or even down to the RSI 2 for very short term trades. The key is to look back at a Daily chart or even intraday charts in the different time frames you trade in and see just how often a price low or price high also saw the RSI tag and reverse off these 30 and 70 signal levels. That is the setting to use!