The Stochastic, made famous by George Lane from the 1950s onward, starts from a different question than the RSI: not "how strong is the push?" but "where is price choosing to close within the territory it has covered recently?". Closes near the window's highs tell of buyers in control into the bell; closes near the lows, of sellers. Lane's insight: at turning points, it is often the closes that weaken first, before the extremes do.
In plain terms — Picture the last two weeks' range as a corridor. The Stochastic tells you at which point of the corridor price decides to stop every evening: always near the upper door, always near the lower one, or halfway along.
How it is built
%K = 100 × (Close − 14-period low) / (14-period high − 14-period low)
The result is the close's percentage position within the window's range: 100 = closing exactly on the high, 0 = on the low. In the slow version (14, 3, 3) — the most used — %K is smoothed over 3 periods and paired with %D, its 3-period average, which acts as the confirmation line.
| Zone | Reading (in a sideways market) |
|---|---|
| > 80 | Closes packed against the window's highs |
| < 20 | Closes packed against the lows |
| %K/%D cross at the extremes | Lane's classic signal |
How to read the chart — Top: a ranging market, the tool's habitat. Bottom: %K (gold), dashed %D (teal), 80/20 thresholds. Interactive — the highlighted points show the oversold cross at the range's edge, the upper extreme and Lane's original idea.
Reading it in practice
- In ranges, at the extremes — the textbook use: %K crossing %D above 80 or below 20 while price sits at the edge of the range. The combination extreme position + cross + price level is what separates a signal from a coincidence.
- Confirm with structure — the cross alone repeats dozens of times; it counts when it coincides with a support or resistance observable on price.
- In trends it changes job — like the RSI, in a strong trend the Stochastic flattens into the extreme zone and stays there. There the useful reading flips: %K dipping below 80 and climbing back becomes a map of pullbacks, not a reversal signal.
Limits and traps
Warning — The Stochastic is the most nervous of the momentum family: it normalises on the recent range, and if that range is small, tiny moves swing it from 20 to 80. On short timeframes without a regime filter (ADX) it produces serial crosses, almost all meaningless.
- The fast version (unsmoothed) is nearly unusable for noise; the modern convention is the slow one (14, 3, 3).
- Above 80 does not mean "expensive" and below 20 does not mean "cheap": it only means near the edge of the recent corridor.
Links
- rsi — measures the intensity of the push; the Stochastic measures the position of the close
- cci — the third perspective: distance from the typical price
- adx — the filter that says when to trust the 80/20 zones
- price-range · sideways-market · indicatori