What RSI period is best?

14 is the standard. Shorter periods react faster but give more false signals; longer periods are smoother. Test on your market.

Blog / Technical

RSI Indicator Explained: Overbought, Oversold and Divergence

The RSI measures momentum on a 0-100 scale. Learn what 70 and 30 really mean, how divergence works and when RSI fails.

What RSI measures

The Relative Strength Index compares recent gains with recent losses over a set number of periods (14 by default) and scales the result from 0 to 100. High readings mean recent moves were mostly up; low readings mean mostly down.

70 and 30 are not sell and buy

Readings above 70 are called overbought and below 30 oversold, but in a strong trend RSI can stay overbought for weeks. Selling only because RSI is above 70 is a classic way to fight a trend and lose.

In ranging markets the levels work better as warnings. In trends, many traders use 40-50 as support in an uptrend and 50-60 as resistance in a downtrend.

Divergence

Bearish divergence happens when price makes a higher high but RSI makes a lower high, showing momentum fading. Bullish divergence is the opposite at lows. Divergence warns that a move is tiring; it does not time the reversal, so wait for a break of structure before acting.

Using RSI sensibly

Combine RSI with support and resistance and a trend filter such as a moving average. Backtest your settings: the 14-period default is not magic. You can test an RSI strategy on real history in our backtester.

Example: RSI in a range

A pair has moved sideways between 1.0800 and 1.0900 for a month. RSI falls to 28 as price touches 1.0800 and a bullish candle forms. A trader buys with a stop below 1.0790 and targets the middle of the range, around 1.0850, where RSI is near 50.

The same signal in a strong downtrend would be a trap, because RSI can stay under 30 while price keeps falling. Always ask whether the market is ranging or trending first.

Key takeaways

RSI measures momentum, not direction.
Overbought can stay overbought in a trend.
Divergence is a warning, not an entry.
Combine RSI with structure.

FAQ

What RSI period is best? 14 is the standard. Shorter periods react faster but give more false signals; longer periods are smoother. Test on your market.

Educational content, not financial advice.