---
title: "Atlas Venture Opportunity Fund II, L.P. — Ownership Dossier"
canonical: https://whiteintel.dev/entity/7cc46103-3e0c-503b-b03f-2c8aa4df1f81
json: https://whiteintel.dev/api/public/dossier/7cc46103-3e0c-503b-b03f-2c8aa4df1f81
identifier: sec:0001885327
jurisdiction: US
risk: Low
source: WhiteIntel corporate-ownership graph
---

# Atlas Venture Opportunity Fund II, L.P.

**Type:** Person  
**Jurisdiction:** [US](https://whiteintel.dev/jurisdictions/us)  
**Identifier:** `sec:0001885327`  
**Risk level:** Low  
**Canonical dossier:** https://whiteintel.dev/entity/7cc46103-3e0c-503b-b03f-2c8aa4df1f81  
**Structured JSON / MCP:** https://whiteintel.dev/api/public/dossier/7cc46103-3e0c-503b-b03f-2c8aa4df1f81  

## Ownership & control

### Holdings / subsidiaries

- **Sionna Therapeutics, Inc.** (10% owner) — https://whiteintel.dev/entity/36003c1e-2a7d-5ea2-a95f-e01c345a874c
- **Sionna Therapeutics, Inc.** (10% owner) — https://whiteintel.dev/entity/36003c1e-2a7d-5ea2-a95f-e01c345a874c
- **Sionna Therapeutics, Inc.** (tenpercentowner) — https://whiteintel.dev/entity/36003c1e-2a7d-5ea2-a95f-e01c345a874c
- **Korro Bio, Inc.** (tenpercentowner) — https://whiteintel.dev/entity/71e9bcfd-4176-551b-b776-01b734a2fd82
- **Q32 Bio Inc.** (tenpercentowner) — https://whiteintel.dev/entity/08894b83-faf4-53f2-980d-374ae48ff38a
- **Dyne Therapeutics, Inc.** (tenpercentowner) — https://whiteintel.dev/entity/6f3d0b50-7aa7-52a8-a2f9-11ef56e96f8c
- **Disc Medicine, Inc.** (tenpercentowner) — https://whiteintel.dev/entity/6d317465-e113-5fee-9632-915c2579af2d
- **Day One Biopharmaceuticals, Inc.** (tenpercentowner) — https://whiteintel.dev/entity/f84c84e2-4e61-565b-94e2-fe9a1c41646f

## Get the full, resolved dossier (agent-callable)

The above is the free teaser. The resolved **multi-hop UBO chain**, ownership **%**, full **financial history**, itemised **assets** and the hop-by-hop **exposure path** are the paid depth — callable as tools from your agent:

```bash
npx -y @whiteintel/mcp-server   # then: get_dossier · trace_ownership_path · check_offshore_exposure
```

Or unlock a one-off cited dossier for **Atlas Venture Opportunity Fund II, L.P.** — https://whiteintel.dev/entity/7cc46103-3e0c-503b-b03f-2c8aa4df1f81 · pricing https://whiteintel.dev/pricing.

---

_This is the markdown-for-agents view of the WhiteIntel dossier for **Atlas Venture Opportunity Fund II, L.P.**. Human view: https://whiteintel.dev/entity/7cc46103-3e0c-503b-b03f-2c8aa4df1f81 · Structured JSON: https://whiteintel.dev/api/public/dossier/7cc46103-3e0c-503b-b03f-2c8aa4df1f81._

_Risk levels are heuristic investigative leads, not legal determinations of beneficial ownership. Every claim carries a source; an absent edge means "not yet observed in current sources", not "does not exist"._