I just read a very interesting story about RSI because it reminds many traders who have suffered heavy losses using this indicator. In reality, RSI is a momentum measurement tool that most people misunderstand.

The problem is that many think RSI is a ready-made reversal indicator, buying when oversold and selling when overbought, and then it's done. But professionals use it to read market momentum, not to predict reversals. This is the crucial difference for sustainable trading.

RSI stands for Relative Strength Index, created by J. Welles Wilder Jr. in 1978. However, its name can be confusing. Relative Strength does not mean comparing Asset A to Asset B in strength, but rather comparing buying pressure to selling pressure within that asset itself. The key point is that RSI is a tool to measure which side is dominating the market.

The formula is very simple: RS = Average Gain divided by Average Loss. If buying pressure wins, RSI will rise above 50. If selling pressure wins, RSI will fall below 50. The 50 line is the true equilibrium point, not 70 or 30.

This is the important point: when you first open a chart, you'll see the 70 and 30 lines, and textbooks will tell you to buy at 30 and sell at 70. It sounds simple, but this is the most dangerous trap. In a strong uptrend, RSI can stay above 70 for several weeks. If you rush to sell, you're fighting the trend, risking your portfolio's life. Similarly, in a downtrend, RSI can stay below 30 for a long time. Rushing to buy is like catching a falling knife.

The technique that professionals actually use is divergence. This is a powerful early warning signal. Bullish divergence occurs when the price makes a lower low, but RSI makes a higher low, indicating selling pressure is waning. Bearish divergence occurs when the price makes a higher high, but RSI makes a lower high, indicating buying pressure is weakening.

A stronger technique is failure swings. If RSI forms a divergence and then breaks through its previous low or high, that confirms a genuine momentum change.

For trend-following traders, the 50 line may be more important than 70 and 30. As long as RSI stays above 50, the market is in a bullish mode. As long as it stays below 50, it's in a bearish mode. This technique helps you understand the main trend direction.

But it's still not complete. Never rely on RSI alone. Professionals use confluence—looking for confirmation signals from multiple tools simultaneously. For example, waiting for bearish divergence on RSI and the price hitting a key resistance level, or waiting for RSI to cross below 50 along with a bearish engulfing candle.

Remember, RSI is a momentum indicator, not a crystal ball that precisely signals buy or sell points. Most mistakes are not caused by the indicator itself but by users' misunderstandings. When RSI rises high, it doesn't mean a reversal is imminent; it indicates strong buying momentum at that moment. If you understand this difference, your trading approach will change so drastically it’s like becoming a different trader.