Private fund adviser · Norwalk, CT
Ardsley Partners
Ardsley Advisory Partners LP · SEC-registered investment adviser · CRD 301116 · SEC 801-114966
At a glance
Ardsley Partners is an SEC-registered investment adviser based in Norwalk, Connecticut, with $1.6 billion in regulatory assets under management as of its Form ADV filed May 6, 2026. Its largest client group by assets is pooled investment vehicles. By Form ADV it is a private fund adviser, ranked 1,851st of 4,686 private fund advisers and 4,065th of 17,210 SEC-registered advisers by assets.
Main office 203-564-4200ardsley.comAs filed on Form ADV
- Regulatory AUM
- $1.6B
- Rank among private fund advisers
- #1,851 of 4,686
- Rank among all SEC RIAs
- #4,065 of 17,210
- Rank in Connecticut
- #168 of 507
- Clients
- 11
- Accounts
- 11
- Discretionary
- 100% of AUM
- Employees
- 11
- Advisory staff
- 7
- Offices
- 1
Owners and executives on its Form ADV
- Philip J. HemplemanLimited Partner
- Kirk D. BalzerLimited Partner
- Steven N. NapoliLimited Partner, Chief Financial Officer, Chief Compliance Officer
- Spencer J. HemplemanLimited Partner
- Benjamin I. BlockLimited Partner
Custody and brokerage
Who it serves
| Client type | Clients | Regulatory AUM | Share |
|---|---|---|---|
| Pooled investment vehicles | 9 | $1.4B | 87% |
| Other | 2 | $209M | 13% |
Private funds
Ardsley Partners reports 6 private funds with $838M in gross assets: hedge funds (Form ADV Item 7.B).
Disciplinary disclosures
Ardsley Partners reports no disciplinary disclosures in Item 11 of Form ADV. Read the details on the SEC’s adviser search ↗
Services
- Portfolio management for pooled investment vehicles
- Portfolio management for businesses and institutions
How it’s paid
- A percentage of assets under management
- Performance-based fees
Form ADV and brochures on the SEC’s adviser search ↗ardsley.com ↗
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The full record on Ardsley Partners
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, 6 years of filings
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- Growth over one, three and five years
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- Rank against 1,933 peers of its type and size
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- Owners and executives, with titles and stakes
- 5 namedLocked
- Main office, fax and compliance officer
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- Filing changes this year, with alerts
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Free while Atlas launches: create a free account and confirm your email. Every figure comes from SEC filings.
Background
Questions
How much does Ardsley Partners manage?
Ardsley Partners reports $1.6 billion in regulatory assets under management across 11 accounts, 100% of it on a discretionary basis, on its Form ADV filed May 6, 2026.
What kind of firm is Ardsley Partners?
Ardsley Partners is a private fund adviser by its Form ADV answers. Private funds are at least half of its business by assets.
Who are Ardsley Partners’s clients?
By assets, its largest client types are pooled investment vehicles ($1.4 billion, 9 clients); other ($209 million, 2 clients).
Does Ardsley Partners manage private funds?
Yes. It reports 6 private funds with $838 million in gross assets, including hedge funds.
Does Ardsley Partners have any disciplinary history?
Ardsley Partners reports no disciplinary disclosures in Item 11 of its Form ADV. Check the SEC’s adviser search for the latest record.
Where these numbers come from
Every figure is Ardsley Partners’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 (2026-05-06), 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 →