Smart Money Volume Index [AlgoAlpha]

🟠OVERVIEW
This script measures buying and selling interest by comparing how price behaves on rising volume versus falling volume. It separates what is often called “smart money” activity from more passive volume and turns that relationship into a normalized index. The result is an oscillator that shows whether buyers or sellers are in control, how strong that control is, and when interest reaches extreme levels that tend to matter for reversals or continuations.

🟠CONCEPTS
The calculation starts by splitting volume flow into two streams. Positive Volume Index (PVI) reacts when volume expands, while Negative Volume Index (NVI) reacts when volume contracts. Each stream is detrended with a long EMA and passed through an RSI calculation to express relative pressure. These two RSIs are then compared as ratios to estimate buy-side and sell-side interest. The values are summed over a rolling window and normalized against historical peaks so the output stays bounded and comparable across markets. In simple terms: relative behavior on high-volume vs low-volume bars defines interest, and normalization makes that interest readable over time.

🟠FEATURES

1. Two display modes: Compare (separate buy and sell interest) and Net (single combined oscillator)
   
2. High-interest threshold zones with visual highlights
   
3. Alert conditions for threshold crosses and zero-line shifts
   

🟠USAGE

1. Setup: Add the script to your chart. Choose Net mode for a clean momentum-style read, or Compare mode to see buy and sell interest separately. Start with the default periods, then adjust the Index Period to control how much history is included.
   
2. Read the chart: Values above zero mean buy-side interest dominates; below zero means sell-side interest dominates. In Compare mode, the green line tracks buying interest and the red line tracks selling interest. When either side pushes beyond the high-interest threshold, participation is elevated and moves tend to be more meaningful.
   
3. Settings that matter: Increasing the Index Period smooths the index and focuses on longer participation trends. Changing the Volume Flow Period alters how sensitive the RSI-based pressure is. The High Interest Threshold controls how selective extreme signals are and directly affects alerts and zone highlights.