Stochastic Oscillator¶

OVERVIEW¶

The stochastic oscillator is a bounded momentum indicator (0–100) that measures where the current closing price sits within the recent high-low range. Developed by George Lane in the late 1950s, it reflects the observation that prices close near session highs during uptrends and near session lows during downtrends.

Note

The stochastic oscillator measures the relative position of price within its recent range — not price direction. It is not a trend indicator.

Threshold	Condition
Above 80	Overbought
Below 20	Oversold
20–80	Neutral range

FEATURES¶

Signal Lines¶

The oscillator plots two lines:

Line	Description
%K	Fast line — raw position of close within the lookback range
%D	Slow line — 3-period simple moving average of %K

Oscillator Variants¶

Variant	Description
Fast Stochastic	Raw %K plotted with its 3-period SMA; more reactive, more noise
Slow Stochastic	%K pre-smoothed with a 3-period SMA before %D is applied; standard default
Full Stochastic	Custom smoothing periods on both lines; exposed by default in Tapeboard

Tip

The Full Stochastic is recommended for most workflows. Adjust smoothing periods in the indicator settings panel to match your timeframe and instrument volatility.

Formula¶

%K = ((C − L₁₄) / (H₁₄ − L₁₄)) × 100

%D = 3-period SMA of %K

Variable	Definition
C	Most recent closing price
L₁₄	Lowest low over the lookback period (default: 14)
H₁₄	Highest high over the lookback period (default: 14)

HOW TO USE¶

Mean-Reversion Entries¶

Long signal — %K crosses above %D while both lines are below 20
Short signal — %K crosses below %D while both lines are above 80

Divergence¶

Bearish divergence — price makes a new high while %K prints a lower high; signals momentum exhaustion before a potential top
Bullish divergence — price makes a new low while %K prints a higher low; signals potential reversal to the upside

Worked Example — SPY¶

Assume SPY over the last 14 sessions has a high of $510, a low of $485, and closes at $505.

%K = (($505 − $485) / ($510 − $485)) × 100
%K = ($20 / $25) × 100
%K = 80

A %K reading of 80 places SPY at the upper boundary of its 14-day range. If %D was 75 the prior session and rose to 78, the %K-above-%D crossover in overbought territory is the classic long exit signal.

Note

If SPY then makes a new high at $512 while %K prints only 76, that lower stochastic high against a higher price high is a bearish divergence — one of the most common short-term top signals.

Confirmation and Multi-Timeframe Use¶

Use Case	Approach
Signal filtering	Combine with RSI or MACD to reduce false crossovers
Trend bias	Use daily stochastic to establish directional lean
Entry timing	Use 60-minute stochastic to refine entry within the daily trend
Range-bound markets	Most reliable when price oscillates within a defined channel

Lookback Period Sensitivity¶

Period	Effect
Short (e.g., 5)	More responsive, higher noise, more false signals
Default (14)	Balanced responsiveness and smoothing
Long (e.g., 21)	Smoother output, lags reversals

LIMITATIONS¶

Note

Be aware of the following constraints before incorporating the stochastic oscillator into a live strategy.

Limitation	Detail
Trend pinning	In strong trends, %K can remain above 80 or below 20 for extended periods; fading these readings causes repeated losses
Whipsaws	The fast variant generates frequent crossovers that produce false signals in choppy or low-volatility tape
Overbought ≠ short signal	A high reading means the close is near the recent range high — not that price is overvalued in any absolute sense
No price target	The indicator signals momentum state only; profit targets must be derived from price-based methods such as support/resistance or ATR multiples

KEYBOARD SHORTCUTS¶

Action	Shortcut
Add Stochastic Oscillator to chart	`Shift` + `S`
Open indicator settings	`I`
Toggle indicator visibility	`Alt` + `H`
Cycle between Fast / Slow / Full variants	`Alt` + `V`
Reset to default parameters	`Ctrl` + `R`

See also: RSI · MACD · Bollinger Bands · Moving Average · Average True Range