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Technical analysis

What is the RSI indicator and how do you use it?

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Short answer

The Relative Strength Index (RSI) is a momentum indicator, created by J. Welles Wilder in 1978, that compares the size of recent gains with recent losses on a scale from 0 to 100. By default it uses 14 periods. Readings above 70 are called overbought and below 30 oversold, but in strong trends RSI can stay there for a long time, so it works best combined with trend and support or resistance.

How RSI is calculated

For each of the last 14 periods, RSI separates up-moves from down-moves. It averages each (Wilder used a smoothed average), divides the average gain by the average loss to get relative strength (RS), and converts it: RSI = 100 − 100 ÷ (1 + RS). If gains and losses are equal, RS is 1 and RSI is 50. A run of only gains pushes RSI toward 100.

Reading the levels

RSI readingCommon interpretationCaution
Above 70Overbought — momentum stretched upwardIn uptrends RSI often stays 60–80
50Balance between buyers and sellersCrossing 50 can confirm trend direction
Below 30Oversold — momentum stretched downwardIn downtrends RSI often stays 20–40

Divergence

Bearish divergence: price makes a higher high but RSI makes a lower high, a sign momentum is fading. Bullish divergence: price makes a lower low but RSI makes a higher low. Divergence can last through several swings before price turns, so traders wait for confirmation — a break of a trendline or a reversal candle at a key level.

Practical ways to use RSI

  • Trend filter: in an uptrend, buy pullbacks when RSI dips toward 40–50 and turns up, instead of shorting at 70.
  • Reversal setups: look for oversold readings only when price is also at strong support.
  • Multiple time frames: daily RSI for direction, 1-hour RSI for timing.
  • Settings: 14 is the standard; shorter (7–9) is faster but noisier, longer (21) is smoother.

Mistakes to avoid

  • Selling every time RSI crosses 70 in a strong uptrend.
  • Using RSI alone without price structure.
  • Changing settings until the indicator fits past data perfectly (curve fitting).
  • Forgetting that RSI lags — it is calculated from past prices.

Roman Urdu mein jawab

RSI indicator kya hai?

RSI (Relative Strength Index) momentum indicator hai jo 0 se 100 ke scale par haalia faidon aur nuqsanaat ka muqabla karta hai, default 14 periods. 70 se upar overbought aur 30 se neeche oversold kehlata hai, lekin strong trend mein RSI kaafi der wahan reh sakta hai — is liye trend aur support/resistance ke saath istemal karein.

Frequently asked questions

What is the best RSI setting for day trading?

Many day traders keep 14 and use it on 5- or 15-minute charts; some use 7–9 for faster signals. No setting works in all markets.

Is RSI good for crypto?

RSI works the same way on crypto, but crypto trends can be extreme, so overbought readings often persist. Combine it with trend and levels.

What is the difference between RSI and stochastic?

Both are 0–100 momentum oscillators. RSI compares average gains with losses; the stochastic compares the close with the recent high-low range.

Where can I add RSI to a chart?

Almost every charting platform and broker app includes RSI in its indicator list; TradingView and MetaTrader both show it by default settings of 14.

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Sources

  1. J. Welles Wilder — New Concepts in Technical Trading Systems (1978)
  2. CMT Association — Technical analysis body of knowledge

This article is general education, not financial, legal or religious advice. Rules change; check the linked primary sources and consult a qualified adviser or scholar before acting. Trading can lose you more than you expect.