# Rush Island Management, LP 13F holdings

> Latest reported SEC 13F equity book. Teaser: top 10 of 22 long-equity positions.
> CIK 1736465. Latest filing Q1 2026, as of quarter end 2026-03-31. Long-equity book $1.5B.

## Top holdings (teaser)

| # | Ticker | Issuer | Value | % of book | Change |
|---|--------|--------|-------|-----------|--------|
| 1 | n/a | Essex Ppty TR Inc | $195.5M | 13.1% | Added |
| 2 | n/a | Sba Communications Corp | $168.4M | 11.3% | Reduced |
| 3 | n/a | Kilroy Realty Corp | $137.1M | 9.2% | Added |
| 4 | n/a | NNN REIT Inc | $130.3M | 8.7% | Reduced |
| 5 | n/a | Healthcare Rlty TR | $122.8M | 8.2% | Reduced |
| 6 | n/a | Ventas Inc | $114.7M | 7.7% | Reduced |
| 7 | n/a | Invitation Homes Inc | $105.3M | 7.1% | New |
| 8 | n/a | First Indl Rlty TR Inc | $101.5M | 6.8% | Reduced |
| 9 | n/a | Federal Rlty Invt TR New | $67.8M | 4.5% | Reduced |
| 10 | n/a | Independence Rlty TR Inc | $51.5M | 3.5% | New |

## Latest moves

Bought: Invitation Homes Inc, Independence Rlty TR Inc, Agree Rlty Corp
Sold: Sba Communications Corp, NNN REIT Inc, Healthcare Rlty TR

Counts and totals reflect the 13F filers and securities Arkolith tracks, not the entire institutional universe. Option legs are excluded from the book above.

## Full data via the API and MCP

This page is a teaser. The complete book, full quarter-over-quarter history, and per-datapoint
provenance are available through the metered REST API and MCP server.

- Endpoint: https://arkolith.com/api/mcp (transport: streamable-http)
- Auth: Bearer API key. Mint one and copy a ready-to-paste command at https://arkolith.com/connect
- Claude Code: `claude mcp add --transport http arkolith https://arkolith.com/api/mcp --header "Authorization: Bearer YOUR_API_KEY"`
- Discovery: `tools/list` is free; `tools/call` is metered by credits.

### Machine-readable
- Tool catalog JSON: https://arkolith.com/api/mcp/catalog
- MCP descriptor: https://arkolith.com/.well-known/mcp.json
- OpenAPI 3.1 REST spec: https://arkolith.com/openapi.json
- Full LLM guide: https://arkolith.com/llms-full.txt
- Human docs: https://arkolith.com/docs

## Source and method

- Source: SEC EDGAR 13F-HR (public domain). Long-equity positions only (option legs excluded). Filed quarterly, about a 45-day lag.
- Primary source: https://www.sec.gov/Archives/edgar/data/1736465/000121465926006469/xslForm13F_X02/primary_doc.xml
- Human page: https://arkolith.com/fund/rush-island-management-lp-1736465
- Per-datapoint lineage: call the `provenance.get` MCP tool for the source URL and fetch history behind any figure.

Paid product with a one-time evaluation grant at signup (no card to evaluate). Most calls cost 1 credit (~$0.01); heavier point-in-time / cross-source tools cost more.

_Latest disclosed public filings. Data, not investment advice._