QuanTAlib/lib/dynamics/qstick/Qstick.md

QSTICK: Qstick Indicator

The average candlestick body reveals the market's true conviction.

Property	Value
Category	Dynamic
Inputs	OHLCV bar (TBar)
Parameters	period (default DefaultPeriod), useEma (default DefaultUseEma)
Outputs	Single series (QSTICK)
Output range	Varies (see docs)
Warmup	period bars
PineScript	qstick.pine

• The Qstick indicator, developed by Tushar Chande, computes a moving average of the close-minus-open difference over a lookback period, quantifying ...
• Similar: CMO, Impulse | Complementary: Volume for confirmation | Trading note: Qstick averages (Close−Open); positive = buying pressure, negative = selling pressure.
• Validated against TA-Lib, Skender, and Tulip reference implementations where available.

The Qstick indicator, developed by Tushar Chande, computes a moving average of the close-minus-open difference over a lookback period, quantifying whether bars are predominantly bullish or bearish. Positive values indicate closes above opens (buying pressure); negative values indicate closes below opens (selling pressure). It supports both SMA (O(N) space via ring buffer) and EMA (O(1) space) smoothing modes and requires TBar input for open/close access.

Historical Context

Tushar Chande introduced Qstick as part of his candlestick quantification work in The New Technical Trader (1994, co-authored with Stanley Kroll). Traditional candlestick analysis relies on visual pattern recognition; Qstick reduces bar body direction and magnitude to a single continuous number suitable for systematic tracking. The indicator addresses a specific gap: close-to-close momentum indicators miss intrabar dynamics captured by the open-to-close differential. The name "Qstick" reflects the "quick stick" reading of candlestick conviction.

Architecture & Physics

1. Body Difference

d_t = \text{Close}_t - \text{Open}_t

Positive d_t represents a bullish bar (close above open), negative represents bearish, zero represents a doji.

2. Moving Average Smoothing

SMA mode: Maintains a ring buffer of N differences and a running sum for O(1) incremental updates:

\text{Qstick}_t = \frac{1}{N} \sum_{i=0}^{N-1} d_{t-i}

EMA mode: Standard recursive filter with decay \alpha = 2/(N+1):

\text{Qstick}_t = \alpha \cdot d_t + (1 - \alpha) \cdot \text{Qstick}_{t-1}

EMA mode uses O(1) space but weights recent bars more heavily than SMA.

3. Complexity

Metric	SMA Mode	EMA Mode
Time	O(1) per bar	O(1) per bar
Space	O(N) ring buffer	O(1)
Ops	1 add, 1 sub, 1 div	1 sub, 1 mul, 1 FMA

Mathematical Foundation

Parameters

Parameter	Type	Default	Constraint	Description
period	int	14	> 0	Lookback period for moving average
useEma	bool	false	—	Use EMA (true) or SMA (false)

Zero-Crossing Interpretation

Condition	Meaning
Qstick > 0	Closes above opens dominate (net buying pressure)
Qstick < 0	Closes below opens dominate (net selling pressure)
Qstick crosses zero	Shift in intrabar momentum direction
Qstick rising	Increasing bullish pressure regardless of sign
Qstick falling	Increasing bearish pressure regardless of sign

Scale Dependence

Qstick values are in absolute price units, not normalized. Cross-instrument comparison requires normalization (e.g., divide by ATR or price level). Short periods (5-8) suit trading signals; longer periods (20+) suit trend identification.

Performance Profile

Operation Count (Streaming Mode)

QStick is an SMA (or EMA) of (Close − Open), tracking average body momentum over N bars.

Post-warmup steady state (per bar):

Operation	Count	Cost (cycles)	Subtotal
SUB (Close − Open)	1	1	1
RingBuffer ADD + oldest SUB (running sum)	2	1	2
MUL × 1/N (average)	1	3	3
Total	4	—	~6 cycles

One of the fastest dynamics indicators: a single subtraction plus an O(1) running sum. ~6 cycles per bar.

Batch Mode (SIMD Analysis)

Operation	Vectorizable?	Notes
Close − Open differences	Yes	VSUBPD — fully independent
Prefix sum	Partial	Sum scan; SIMD prefix-sum pattern
Windowed average	Yes	VSUBPD on prefix + VMULPD (×1/N)

Fully SIMD-vectorizable in batch mode. AVX2 achieves ~4× throughput on large arrays.

Quality Metrics

Metric	Score	Notes
Accuracy	10/10	Exact arithmetic; trivial SMA of differences
Timeliness	8/10	SMA period only; no secondary smoothing lag
Smoothness	7/10	N-period averaging removes single-bar outliers
Noise Rejection	6/10	No adaptive bandwidth; outlier body candles shift the average

Resources

• Chande, T. S. & Kroll, S. (1994). The New Technical Trader. John Wiley and Sons.
• Kirkpatrick, C. D. & Dahlquist, J. R. (2015). Technical Analysis: The Complete Resource for Financial Market Technicians. FT Press.