GiveRate / All records / Forbes 400 (Sept. 2026) / Marilyn Simons & family
Marilyn Simons & family
20%+
Marilyn Simons & family has given an estimated 20%+ of current net worth ($36.6B), based on Forbes' philanthropy score.
- GiveRate
- 20%+
- Net worth
- $36.6B
- Stated lifetime giving
- Not stated
- Forbes 400
- #27 · Hedge funds · East Setauket, New York
- Status
- Source-reported range
- Sources
- Forbes 400 profile · Sept. 2026
The math
Forbes philanthropy score 5 of 5: lifetime giving is 20%+ of current net worth. The range is Forbes' own banding; GiveRate shows it as published.
Profile
- Age
- 75
- Residence
- East Setauket, New York
- Industry
- Finance & Investments
- Source of wealth
- Hedge funds
- Self-made
- No (inherited or family wealth)
- One-year change
- $32.5B (#29) in Sept. 2025 to $36.6B (#27) in Sept. 2026, a gain of 13%.
What the range means in dollars
Forbes gives Marilyn Simons & family a philanthropy score of 5 out of 5, meaning lifetime giving equals 20% or more of current net worth. On a $36.6B fortune, that implies lifetime giving of at least $7.3B. 13 of the 400 share this score, 370 score lower and none score higher.
For scale: 20% or more of a $50,000 household income would be $10,000 or more.
Giving on record
She chairs the $4.5 billion (assets) Simons Foundation, which is the primary funder of Math for America.
From the Forbes profile (Sept. 2026).
Others in Finance & Investments
- Warren Buffett: ≥33.3% · $144B
- Thomas Peterffy: Under 1% · $107B
- Michael Bloomberg: ≥21.1% · $94.9B
- Jeff Yass: Under 1% · $77.8B
- Ken Griffin: 4.3% · $60.5B
- Stephen Schwarzman: 1–5% · $46.4B
Others in New York
- Michael Bloomberg: ≥21.1% · $94.9B
- Julia Koch & family: 1–5% · $84.6B
- Stephen Schwarzman: 1–5% · $46.4B
- Israel Englander: Under 1% · $27.6B
- Rupert Murdoch & family: Under 1% · $25.0B
- Edwin Chen: Under 1% · $18.0B
Questions
How much has Marilyn Simons & family given to charity?
Forbes scores Marilyn Simons & family 5 of 5 for philanthropy, meaning lifetime giving of 20% or more of net worth, at least $7.3B on a $36.6B fortune.
What is Marilyn Simons & family's net worth?
Forbes estimates $36.6B as of September 2026, ranking #27 on the Forbes 400.
What is Marilyn Simons & family's GiveRate?
20%+. GiveRate is lifetime giving as a share of wealth, built from published Forbes figures. See giverate.org/methods/ for the method.
GiveRate is an estimate built only from the published figures above. Wealth and giving totals are themselves estimates. See methods. Spot an error? Request a correction. See all Forbes 400 (Sept. 2026) · Open in the interactive rankings · Calculate your own GiveRate