Feature Request: Point and Figure (PnF) Traditional Box Scaling

Nobody has claimed this yet.

First, thank you for the great work on mplfinance!

I would like to request the addition of Traditional Box Scaling for Point and Figure (P&F) charts.

Currently, mplfinance supports fixed box scaling and dynamic ATR scaling. While these approaches are helpful, they both have important limitations in practice:

- Fixed box scaling fails to stay consistent across price levels. For example, a $1 move represents a 10% change when a stock is priced at $10, but only a 1% change when the same stock is priced at $100.
- Dynamic ATR or percent scaling solves this inconsistency but often produces non-round box values, which can be visually and psychologically unintuitive for market participants.

Source: StockCharts.com

The Traditional Box Scaling, originally established by ChartCraft in the 1930s, resolves both these issues. It has long been the standard reference for Point and Figure charting and preserves both visual clarity and percentage consistency across price ranges.

This way, Point and Figure charts are actually very very helpful.

Sources: [https://chartschool.stockcharts.com/table-of-contents/chart-analysis/point-and-figure-charts/point-and-figure-basics/point-and-figure-scaling-and-timeframes](url)

Thank you for your time and for considering this enhancement.


Start by locating mplfinance's Point and Figure chart implementation and the existing fixed box scaling and dynamic ATR scaling paths. Read the linked StockCharts reference to define the traditional scaling rules, then determine the expected behavior and validation needed for charts using the new scaling mode.

Written by the indexing model from the issue text.