Stochastic Oscillator
In simple terms
A tool that helps traders figure out if a cryptocurrency price is too high or too low right now by looking at where today's price falls within recent highs and lows. Think of it like checking if a stock is near the top or bottom of its recent trading range.
Definition
Momentum indicator comparing closing price to price range over a period.
In depth
The Stochastic Oscillator calculates a value (0-100) by comparing the current closing price against the highest high and lowest low over a specified period, typically 14 candles. The formula %K = [(Close - Lowest Low) / (Highest High - Lowest Low)] × 100 indicates overbought conditions above 80 and oversold conditions below 20. A smoothed moving average called %D is often applied to %K to generate trading signals; when %K crosses above %D, it may signal upward momentum, while crosses below suggest downward momentum. Traders use divergences between price action and oscillator readings to anticipate reversals before they occur on the chart.
How does Stochastic Oscillator work?
The stochastic oscillator asks where the latest close sits inside the recent trading range. Over a lookback window, usually 14 periods, it finds the highest high and the lowest low. It subtracts the lowest low from the current close, divides by the full high-to-low range, and multiplies by 100 to produce %K on a 0-100 scale. A three-period average of %K becomes the %D line, and the widely used slow version smooths %K once before averaging again. Above 80 means closes are near the top of the range; below 20, near the bottom.
An example
Over the last 14 periods an illustrative asset's highest high is $60 and its lowest low is $40, and it has just closed at $55. That is $15 of a $20 range, so %K is 75. If the two previous %K readings were 65 and 70, then %D is (65 plus 70 plus 75) divided by 3, or 70. Both figures sit below the conventional 80 line and describe position within a range, nothing more.
Figures are illustrative only.
What beginners get wrong
- Above 80 is commonly misread as a sell signal, but in a sustained uptrend closes cluster near the highs and the oscillator stays elevated.
- Fast and slow versions produce different readings from identical data, so check which one a platform draws before comparing settings with someone else.
- Crossovers of %K and %D in the middle of the range happen constantly and carry far less information than beginners assume.
- In a narrow or illiquid range, a tiny price change spans most of the high-low band and swings the reading from 10 to 90.
Related terms
Part of
What is technical analysis, and how are crypto charts read? — the subject page for technical analysis, with all 29 of its definitions in one place.
Educational only — not financial advice.