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QuanTAlib/lib/dynamics/qstick/Qstick.md
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Miha Kralj 90d5638008 Add new moving average implementations: LTMA, MCNMA, NLMA, NMA, NYQMA, RAIN, and TRAMA
- LTMA (Linear Trend Moving Average): Introduces a predictive moving average using dual cascaded EMAs for trend estimation.
- MCNMA (McNicholl EMA): Implements a zero-lag TEMA using a cascaded EMA structure for enhanced responsiveness.
- NLMA (Non-Lag Moving Average): Utilizes a damped cosine kernel to achieve reduced lag in moving averages.
- NMA (Natural Moving Average): Adapts smoothing based on volatility profiles using a square-root kernel.
- NYQMA (Nyquist Moving Average): Applies the Nyquist-Shannon theorem to prevent aliasing in cascaded moving averages.
- RAIN (Rainbow Moving Average): Combines multiple SMA layers with weighted averages for multi-scale smoothing.
- TRAMA (Trend Regularity Adaptive Moving Average): Adapts smoothing based on the frequency of new highs and lows in price data.
2026-02-20 21:40:32 -08:00

3.6 KiB

QSTICK: Qstick Indicator

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

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)

Pseudo-code

QSTICK(bar, period=14, useEma=false):

  diff = bar.Close - bar.Open

  if useEma:
    // EMA mode
    alpha = 2.0 / (period + 1)
    if count == 0:
      ema_val = diff
    else:
      ema_val = FMA(alpha, diff - ema_val, ema_val)   // alpha*(diff-ema)+ema
    result = ema_val

  else:
    // SMA mode with ring buffer
    if buffer is full:
      running_sum -= buffer.oldest
    buffer.add(diff)
    running_sum += diff
    result = running_sum / min(count, period)

  return result

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.

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.