Atreides is a crossover fund — Baker’s stated thesis is that at every layer of the AI stack the key competitors are simultaneously public and private, so you cannot underwrite one side without the other.1 The private book is invisible in 13Fs; this page reconstructs it from SEC Form D filings (primary source), company press releases, and credible reporting. Confidence levels are marked.
Vehicle Architecture (from SEC Form D — primary source)
EDGAR shows ~57 Atreides-related entities, all Boston. The structure:
| Vehicle | First Form D | Latest data | Role |
|---|---|---|---|
| Atreides Foundation Fund, LP / Ltd. (CIK 1777465 / 1777228) | May 2019 | D/A 2026-05-29: 2.03 B / 260 (offshore Ltd) | Flagship crossover hedge fund (master-feeder). Privates like SpaceX sit in its “VC sleeve” |
| Special Circumstances Fund, LLC, Series A–X (+ mirror Cayman SPC series) | Nov 2019 | Series X filed 2026-05-14 | 24 deal-by-deal private co-invest SPVs, ~$0.8 B total sold onshore. Underlying companies never disclosed |
| Atreides Arrakis Fund, LP (CIK 1950644) | Oct 2022 | $64.5 M / 56 investors at filing | ”Opportunistic venture fund” — structured equity, take-privates2 |
| Valor Atreides AI I L.P. (+ I-A/I-B feeders, CIK 2033590) | Jan 2025 | D/A 2026-02-05: $758.7 M sold / 664 investors | Dedicated AI venture JV with Valor Equity Partners; PitchBook pegs it at ~$780 M |
| Flint Hills Valor Atreides AI L.P. (CIK 2076559) | Jul 2025 | 30 M sold | Parallel/feeder vehicle to the Valor JV |
| Atreides Private Opportunities Fund II, LP / Offshore II (CIK 2121510 / 2121509) | Apr 27, 2026 | $0 sold at filing — currently raising | New dedicated PE-style fund. Form ADV reveals the lineage: the 2022 Arrakis raise lives on as “Atreides Private Opportunities Master Fund I, LP” ($246 M gross, 12/31/2025) |
| Atreides 150/50 Technology Fund + Low Net Fund | Jan 2026 | 5 M initial | New public-markets hedge strategies, listed for completeness |
The Special Circumstances SPV cadence is a deal-flow seismograph: Series Q (19.1 M, Mar 2025), S (11.3 M, Sep 2025), U (55.5 M, Jan 2026), W (**82.6 M, May 2026). Private dealmaking accelerated sharply through late 2025 into 2026.
Confirmed Private Investments
| Company | What | Round / Date | Source |
|---|---|---|---|
| Cerebras Systems | Wafer-scale AI chips — IPO’d May 14, 2026 (Nasdaq: CBRS) | Co-led 8.1 B (Sep 2025); participated 23 B (Feb 2026) | Cerebras PR, TechCrunch, Series H PR |
| Enfabrica | AI networking silicon | Led 900 M for CEO + tech license | Business Wire, CNBC |
| SiFive | RISC-V datacenter IP | Led 3.65 B (Apr 2026) | SiFive PR |
| Crusoe Energy | AI datacenters / power | 10 B (Oct 2025), co-led by Valor + Mubadala | Crusoe newsroom |
| Cognition AI | Devin coding agent | >26 B (May 2026), new investor | Cognition blog |
| Decart | Generative world models | 4 B (May 2026) | CTech |
| Lyte | Robot perception (“physical AI”) | $107 M stealth-exit round (Jan 2026) | Business Wire |
| Loop | Supply-chain AI | Led $95 M Series C (Apr 2026) — via the Valor Atreides AI fund | TechCrunch |
| Astera Labs | AI connectivity (pre-IPO) | 950 M (Sep 2021); Baker: held “since Series C” — now the top public equity position | Intel Capital PR |
| SpaceX | Launch / Starlink — IPO priced at 1.77 T), Nasdaq debut as SPCX set for June 12, 2026 | Long-standing holding; described in 2022 internal docs as the largest position in the fund’s VC sleeve; ~$2.5 B reported value (Apr 2026, single source) | TechCrunch, GuruFocus |
| Xsight Labs | Israeli networking semis | Venture investor; Baker on the board | Atreides team bio |
The pattern is unmistakable: the private book is the same thesis as the public book, one layer earlier. Cerebras/SiFive/Enfabrica/Xsight = compute and connectivity silicon (the private Astera/Credo). Crusoe = watts (the private Vistra/CoreWeave). Lyte/Decart/Cognition = the application/robotics frontier. Several public positions (Astera confirmed; ACV Auctions, Sonder probable; CoreWeave, Chime, EquipmentShare inferred from IPO-window timing only — public funding records don’t name Atreides) began as private-side positions and crossed over at IPO. And the crossover now runs both directions: Cerebras listed in May 2026 and SpaceX lists June 12, 2026, moving the two flagship private marks into the public book.
Probable (weaker sourcing — firm bios, databases)
Earlier venture positions attributed to Atreides in profiles and databases, typically $10–50 M checks: ACV Auctions, Sonder, DriveNets, Druva, K Health, Nexar, Premise Data, Electric AI, Mythic AI.3 Via the Valor Atreides AI fund: Heron Power, Bedrock Robotics (PitchBook).
Explicitly Not Confirmed
Despite Baker’s constant public commentary on them, no source places Atreides in disclosed investor lists for xAI, Anthropic, OpenAI, Anduril, Stripe, Databricks, Groq, Figure, Mistral, Safe Superintelligence, Scale AI, or Neuralink. Two important nuances:
- Valor Equity Partners — the JV partner — is a major xAI backer. A “Valor Atreides AI” LP could plausibly carry indirect xAI exposure, but the Form Ds disclose nothing about underlying assets. Treat as rumor-grade.
- The 24 Special Circumstances SPVs are deal-specific and anonymous; some of the larger 2025–26 series (W at 83 M) plausibly map to the confirmed rounds above (Cerebras H, SiFive G, Cognition D timing all fit), but the mapping is inference, not fact.