Indicators That Earn Their Place
What "overbought" really means, and why it is not a sell signal.
intermediate · 3 min read · 10 XP
The RSI is probably the most misused indicator in retail trading, because its two most famous levels are almost universally misinterpreted. This lesson fixes that.
The RSI — Relative Strength Index — compares the size of recent gains to the size of recent losses and expresses the result on a 0–100 scale.
Roughly: over the last 14 periods, if the average up-move is much larger than the average down-move, RSI is high. If they are similar, RSI sits near 50. If down-moves dominate, RSI is low.
That is all it is. RSI measures the character of recent movement, not value. It has no idea whether price is expensive.
Convention says RSI above 70 is "overbought" and below 30 "oversold". Those words strongly imply "too high, about to fall" and "too low, about to rise". That implication is wrong and it is expensive.
What RSI above 70 actually means: recent up-moves have been much larger than recent down-moves. In other words — the market is trending strongly upward. That is not a reason to sell. It is a description of a strong trend.
The most costly beginner reflex
Shorting because RSI hit 70. In a genuine trend, RSI can sit above 70 for weeks while price continues to make new highs, and every short taken on that basis is a loss. "Overbought" is a description of strength, and strength persists.
1. As a range tool. In a confirmed range — and only there — RSI extremes do align with the range's ceiling and floor. If you have independently established that the market is ranging, RSI 70 at the range top is a reasonable confluence.
2. As a strength comparison. RSI at 75 on one pair and 55 on another tells you which move has more force behind it. This is more useful than either number alone.
3. Divergence. This is the reading most worth learning. Divergence occurs when price makes a new extreme and RSI does not.
Bearish divergence: price makes a higher high, RSI makes a lower high. The new price high was achieved with less force than the previous one. Buyers are working harder for less.
Bullish divergence: price makes a lower low, RSI makes a higher low. The decline is losing energy.
Divergence is a warning, not a trigger
Divergence tells you a move is tiring. It does not tell you when it will stop, and a tiring trend can tire for a very long time. Use it to stop adding to a position, to tighten a stop, or as one condition alongside a level — never as a standalone entry signal on its own.
No — it was early, which for a warning signal is the normal condition. Divergence identifies weakening momentum, and momentum can weaken for a long time before price responds. This is exactly why it belongs in the "reduce risk" toolbox rather than the "enter here" one.
What to remember
RSI measures the character of recent movement, not value. An RSI above 70 describes a strong trend rather than an expensive price, which is why fading it is so costly. Its genuine uses are within confirmed ranges, as a cross-pair strength comparison, and as divergence — a warning that momentum is fading, not an entry trigger.