Private fund adviser · New York, NY
Flexstone Partners, LLC
SEC-registered investment adviser · CRD 147353 · SEC 801-69478
At a glance
Flexstone Partners, LLC is an SEC-registered investment adviser based in New York, New York, with $7.2 billion in regulatory assets under management as of its Form ADV filed September 30, 2026. Its largest client group by assets is pooled investment vehicles. By Form ADV it is a private fund adviser, ranked 761st of 4,686 private fund advisers and 1,664th of 17,210 SEC-registered advisers by assets.
Main office 212-703-0300flexstonepartners.comLinkedInAs filed on Form ADV
- Regulatory AUM
- $7.2B
- Rank among private fund advisers
- #761 of 4,686
- Rank among all SEC RIAs
- #1,664 of 17,210
- Rank in New York
- #428 of 2,591
- Clients
- 48
- Accounts
- 48
- Discretionary
- 53% of AUM
- Employees
- 46
- Advisory staff
- 21
- Offices
- 2
Owners and executives on its Form ADV
- Nitin GuptaManaging Partner
- Benoit JacquinManaging Partner
- Eric DeramManaging Partner
- Hans E. DewitteChief Operating Officer / Chief Financial Officer
- Stephen E. MahannaChief Compliance Officer
- C R. BarrettManaging Partner
- Robert Di GeronimoManaging Partner
- Michael R. DagostinoManaging Partner
- Benjamin MarinoManaging Partner
- Aaron D. BrightManaging Partner
- John R. CancellieriManaging Partner
Custody and brokerage
Custodian
Flexstone Partners, LLC’s Form ADV lists no custodian for separately managed accounts. Firms report one only when they manage $10 million or more in those accounts.
Broker-dealer
Affiliated broker-dealer
It names an affiliated broker-dealer: Natixis Distribution, LLC.
- Natixis Distribution, LLC ↗CRD 34754
An introducing broker-dealer: its trades clear through another firm, which holds the brokerage accounts. Its annual audited report filed with the SEC, February 2026
Who it serves
| Client type | Clients | Regulatory AUM | Share |
|---|---|---|---|
| Pooled investment vehicles | 48 | $7.2B | 100% |
Private funds
Flexstone Partners, LLC reports 42 private funds with $6.6B in gross assets: private equity funds (Form ADV Item 7.B).
Disciplinary disclosures
Flexstone Partners, LLC answers yes to 3 disclosure items in Item 11 of Form ADV (criminal, regulatory or civil matters involving the firm or its advisory affiliates). Read the details on the SEC’s adviser search ↗
Services
- Portfolio management for pooled investment vehicles
How it’s paid
- A percentage of assets under management
- Performance-based fees
Form ADV and brochures on the SEC’s adviser search ↗flexstonepartners.com ↗
AtlasMembers
The full record on Flexstone Partners, LLC
Ten years of SEC filings, its owners and contacts, and how it stacks up against its peers. Atlas members see all of it.
- Assets, accounts, clients and staff, ten years of filings
- Locked
- Growth over one, three and five years
- Locked
- Rank against 1,166 peers of its type and size
- Locked
- Owners and executives, with titles and stakes
- 11 namedLocked
- Main office, fax and compliance officer
- Locked
- Filing changes this year, with alerts
- 5Locked
Free while Atlas launches: create a free account and confirm your email. Every figure comes from SEC filings.
Background
Questions
How much does Flexstone Partners, LLC manage?
Flexstone Partners, LLC reports $7.2 billion in regulatory assets under management across 48 accounts, 53% of it on a discretionary basis, on its Form ADV filed September 30, 2026.
What kind of firm is Flexstone Partners, LLC?
Flexstone Partners, LLC is a private fund adviser by its Form ADV answers. Private funds are at least half of its business by assets. It reports a bank or thrift among its related persons.
Who are Flexstone Partners, LLC’s clients?
By assets, its largest client types are pooled investment vehicles ($7.2 billion, 48 clients).
Does Flexstone Partners, LLC manage private funds?
Yes. It reports 42 private funds with $6.6 billion in gross assets, including private equity funds.
Does Flexstone Partners, LLC have any disciplinary history?
Flexstone Partners, LLC answers yes to 3 disclosure items in Item 11 of Form ADV, which covers criminal, regulatory and civil matters involving the firm or its advisory affiliates. The details are on the SEC’s adviser search.
Where these numbers come from
Every figure is Flexstone Partners, LLC’s own answer on its latest Form ADV, from the SEC’s registered-adviser list as of October 1, 2026: regulatory assets and accounts (Item 5.F), clients by type (5.D), employees (5.A and 5.B), compensation (5.E) and services (5.G). Custodians come from Schedule D 5.K(3) of its latest filing (2026-09-30), which lists those holding 10% or more of separately managed account assets and the amount at each. “Hybrid” means some employees are also registered representatives of a broker-dealer (Item 5.B(2)); affiliated broker-dealers are the related persons it lists in Item 7.A and Schedule D. Firm type comes from its own answers: broker-dealer firms are registered broker-dealers themselves (Item 6.A); private fund advisers manage mostly private funds (Item 7.B, 5.D); wealth managers manage at least half their assets for individuals (5.D). Ranks compare it by regulatory assets with every SEC-registered adviser and with firms of its type. Figures are as of the firm’s last annual update, so they can lag recent deals and market moves. Regulatory AUM counts assets the firm continuously supervises and can differ from what a firm markets.
Not an endorsement or a recommendation. Before hiring any adviser, read its Form ADV Part 2A brochure and check its record on the SEC’s adviser search. How to check a financial advisor →