Net worth
$36.6B
Forbes Real-Time · as of Sep 24, 2026
Latest moves
No moves from Marilyn Simons & family in the digest yet. The archive grows every morning.
Recent SEC filings
SEC filings · last 90 days
Form 4 insider trades post within 2 business days. 13F fund holdings can arrive 45 days after quarter end. New to filings? Read Filings 101.
Footprint
Companies
Wealth derives from Renaissance Technologies (quant hedge fund founded by late husband Jim Simons, d. 2024)heir/family holder
source ↗Stakes
PMV Pharmaceuticals — 4,588,891 shares, 4.9% (reported jointly by Euclidean Capital, Marilyn H. Simons, Ashvin B. Chhabra, Greenland NFP entities, Symmetry Group Ltd.)4.9% · as of Mar 2026
source ↗Euclidean Capital 13F (Q2 2026, $439.8M, 11 positions): largest Vanguard FTSE All-World ex-US ETF $271.6M, Vanguard Value ETF $113.3M, iShares MSCI India ETF $18.3M; biotech stakes in ORIC Pharmaceuticals ($10.7M), Foghorn Therapeutics ($7.7M), Teamshares ($9.0M), PMV, Alector, Surrozen, Tenayaas of Jun 2026
source ↗Investment vehicles
Euclidean Capital LLC (New York)family office · CIK 0001825034 · Files 13F
source ↗More
- Type
- family office
- Notes
- Simons family investment office; files 13F-HR quarterly (latest 2026-08-14 for Q2 2026) and N-PX; Marilyn Simons is a joint 13G reporting person
Greenland NFP B Ltd. / Greenland NFP LLC / Greenland A LLC / Symmetry Group Ltd.holding co
source ↗More
- Type
- holding co
- Notes
- Affiliated entities listed as joint reporting persons with Euclidean/Marilyn Simons
Real estate
East Setauket, New York (listed residence)residence · as of 2026-09
source ↗Giving
Simons Foundation (chair; ~$4.5B assets; primary funder of Math for America; family has given >$10B incl. mathematics, autism research, Stony Brook University)
source ↗Simons Foundation Inc (New York) — total assets $4.59B, expenses $565.0M (tax year 2023 Form 990-PF data)EIN 13-3794889
source ↗Record $500M gift from Jim Simons (with Marilyn Simons) to Stony Brook University, June 2023 (Bloomberg headline; older)
source ↗Research gaps: Pass 2 adds the Simons Foundation EIN and financials from ProPublica. Marilyn Simons's own Section 16 filings (CIK 0001825290) stop in 2021; current holdings are reported through Euclidean Capital's 13F/13G filings. The family's residual Renaissance Technologies interest is still undisclosed, and no 2025-26 gifts were found in reputable sources.