Smart Money Pressure Differential

Purpose
The Smart Money Pressure Differential (SMPD) is built to reveal the underlying tug‑of‑war between informed volume flows represented by NVI and reactive volume flows represented by PVI, using a clean statistical framework. Instead of relying on raw NVI or PVI, which drift over time and are not directly comparable, the script isolates pressure deviations by measuring how far each index moves away from its own long‑term expectation. By standardizing these deviations, SMPD produces a stable, volatility‑normalized spread that highlights accumulation, distribution, and regime transitions with far greater clarity than traditional volume indicators.
How It Works
The script computes NVI and PVI, scales them, and subtracts their EMAs to extract deviation‑from‑trend pressure, with optional WMA smoothing to reduce micro‑noise. Each deviation series is then standardized independently using rolling mean and standard deviation, ensuring both NVI and PVI operate on equal statistical footing. Their difference becomes the SMPD spread, a normalized measure of which side is exerting more pressure. A second layer applies log‑ROC to capture acceleration rather than level, and these acceleration signals can be plotted as dotted lines. Standard deviation reference levels at 0, 1, 2, and 3 provide a consistent frame for interpreting extreme pressure events.
Rationale
This architecture solves structural weaknesses found in most volume‑based tools, particularly scale drift, volatility collapse, and the instability of cumulative indicators. Standardizing before differencing prevents one index from overpowering the other, ensuring the spread reflects true pressure imbalance rather than structural bias. The log‑ROC layer adds a stable acceleration measure that avoids the distortions of classic ROC when values approach zero. The result is a regime‑independent engine, producing signals that remain comparable across assets, timeframes, and market conditions. SMPD therefore becomes a robust diagnostic tool for identifying when smart‑money pressure is building, fading, or reversing, without relying on arbitrary thresholds or bounded oscillators that distort signal strength.