Constructing Spindle Charts with VWMA and Volume Ratio
Summary
The article explains spindle charts, a volume-by-price visualization that combines open, close, high, and low prices with a volume-weighted moving average (VWMA) and a volume ratio (VR). VWMA weights prices by volume over a selected period, while VR compares current volume with its period average. Together, these values form a spindle shape intended to show price movement alongside relative activity.
Most of the article details how to draw the indicator in MQL5. Since built-in plot styles do not support the desired geometry, it uses bitmap objects with angled line images and anchor points to assemble filled or unfilled spindles. The author compares the complexity and resource demands of the two rendering approaches, then describes calculating spindle angles from the price and volume dimensions. The article is primarily an implementation guide, not a validated trading study: it offers no rigorous performance evidence for the indicator, and notes that the plotting approach has memory, speed, and stability costs.
Key ideas
- A spindle chart combines OHLC prices with VWMA and a volume ratio to display price movement and relative activity.
- VWMA is calculated by weighting prices by volume, while VR compares current volume with average volume over a chosen period.
- MQL5's built-in plotting styles do not directly support spindle geometry, so the article constructs it from bitmap objects.
- Unfilled spindles require fewer bitmap resources and are simpler to render than filled spindles.
- The bitmap approach carries memory, performance, and stability tradeoffs, and the article does not establish trading profitability.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.