STC Pass Node

Schaff Trend Cycle — Series Input

MomentumCyclePass

Overview

The STC Pass Node computes the Schaff Trend Cycle on a series input. STC applies a double Stochastic normalization (%K applied twice) to MACD — resulting in a bounded oscillator that is more sensitive to trend changes than MACD alone.

Developed by Doug Schaff, STC combines the cycle detection of a Stochastic oscillator with the trend-following characteristics of MACD. The double smoothing makes it more responsive than either indicator alone, with the output bounded in [0, 100]. Values above 75 are overbought; below 25 are oversold; with particularly strong signals at 100 and 0.

Formula

MACD = EMA(input, fastPeriod) − EMA(input, slowPeriod)

First Stochastic:

%K1[i] = (MACD[i] − min(MACD, n)) / (max(MACD, n) − min(MACD, n)) × 100

%D1 = EMA(%K1, period) ← first smoothing

Second Stochastic:

%K2[i] = (%D1[i] − min(%D1, n)) / (max(%D1, n) − min(%D1, n)) × 100

STC = EMA(%K2, period) ← second smoothing

Output range: [0, 100]. Warm-up: period bars.

Parameters

Parameter	Default	Description
period	10	Stochastic lookback period for both normalization stages

Inputs & Outputs

Slot	Direction	Type	Description
input	Input	{ values, timestamps }	Price or any numeric series
values	Output	(number \| null)[]	STC values in [0, 100]; nulls during warm-up
timestamps	Output	number[]	Unix timestamps aligned to input

Use Cases

Trend Change Detection

STC turning from flat near 100 and beginning to fall (or flat near 0 and beginning to rise) often precedes price trend changes by several bars. The signal is earlier than MACD crossovers and zero-line crossings.

Overbought / Oversold Extremes

STC stuck at 100 confirms a strong uptrend — stay long. STC stuck at 0 confirms a strong downtrend — stay short. The transition off these extreme levels often marks the best entry points for trend-following trades.

MACD Replacement

STC produces more timely signals than MACD with fewer false crossovers. Use STC crossing above 25 as a buy signal and below 75 as a sell signal, replacing MACD zero-line crossovers in trend-following strategies.

Tips & Best Practices

Pinned to Extremes

STC can remain pinned at 0 or 100 during strong trends. This is expected behavior — it means the trend is intact. Only act when the indicator begins moving away from the extreme, not while it sits there.

25/75 Are Better Thresholds

Unlike RSI's 30/70, STC's recommended thresholds are 25 (bullish activation) and 75 (bearish activation). Crossings of 25 upward and 75 downward generate higher-probability signals than 50-line crossovers.

Combine with Volume

STC activation signals (coming off 0 or 100) confirmed by rising volume are significantly more reliable than unconfirmed activations. Use a volume threshold node in parallel to filter STC signals.