Top 13F Holders — Stacked Bar

A canonical ownership chart used in equity research to show institutional positioning over time.

What this chart shows

Each colored band is one institutional holder; the band's vertical thickness at each x-axis position is the number of shares (B) that holder owned at that quarter-end. Over time, you can see holders accumulating, distributing, or exiting.

When to use

• Stock thesis sections discussing positioning, flow, or notable single-holder moves (e.g., a Berkshire exit visible as a shrinking orange band)
• Sector primers showing dominant ownership patterns

How agents use this

data = {
  periods: ["Jul 24", "Oct 24", "Jan 25", ...],
  holders: [
    { name: "Vanguard", shares: [1.32, 1.35, ...] },
    { name: "Berkshire", shares: [0.25, 0.12, 0.05, ...], color: "#e8943a" },
    ...
  ]
}

Agent fills template.html (a Chart.js stacked bar config) with this data shape and returns rendered HTML.

Design notes

• Berkshire band is conventionally orange to make exits/entries visible against a stable Vanguard navy
• Stacked bar (not stacked area) — the discrete quarterly nature of 13F filings warrants discrete visual marks
• Y-axis units: B shares; format as 1.36B sh

Source provenance

This format's structure derives from public sell-side research practice (e.g., GS Marquee Card #5 — "What are the top 13F institutional shareholders of Apple Inc?"). The chart shape is not copyrightable; AlphaInk uses the format as its own implementation.

Example output

See ./preview.html — sample data populated with AAPL holders, July 2024 through January 2026.