# Ardsley Partners

> Ardsley Partners is an SEC-registered investment advisory firm in Norwalk, CT, registered since 2019, reporting $1 billion to $5 billion in regulatory assets under management in its Form ADV filing dated May 6, 2026.

- CRD: 301116
- Filed as: ARDSLEY PARTNERS
- Legal name: Ardsley Advisory Partners LP
- Registration: SEC-registered investment adviser (status as filed: Approved)
- Location: Norwalk, CT
- Filing period: October 2026
- Form ADV filing dated: May 6, 2026
- SEC record (IAPD): https://adviserinfo.sec.gov/firm/summary/301116
- AdvisorCensus page: https://advisorcensus.com/firm/ardsley-partners-norwalk-ct-301116

## Quick answers

**How is Ardsley Partners compensated?**
On its Form ADV (Item 5.E, October 2026), Ardsley Partners reports these compensation arrangements: a percentage of assets under its management; performance-based fees. The amounts are in Item 5 of its Form ADV Part 2A brochure.

**Where is Ardsley Partners located?**
Ardsley Partners' principal office is in Norwalk, CT, according to its Form ADV.

**Is Ardsley Partners registered with the SEC or a state?**
Ardsley Partners is an SEC-registered investment advisory firm, registered since 2019. Status as filed: Approved. CRD 301116.

**How much does Ardsley Partners manage?**
Ardsley Partners reports $1,635,701,621 in regulatory assets under management in its Form ADV filing dated May 6, 2026 (100% discretionary).

**How have Ardsley Partners' assets and staff changed since 2021?**
In the Form ADV data for Ardsley Partners: Regulatory assets under management: $1,197,794,786 in the October 2021 data and $1,635,701,621 in the October 2026 data, up 37%. Total employees: 12 in October 2021 and 11 in October 2026. Assets under management move with markets as well as with clients coming and going.

**What types of clients does Ardsley Partners serve?**
By number of clients on Form ADV Item 5.D: pooled investment vehicles (other than investment companies and business development companies) (9); other (2).

**Which custodians does Ardsley Partners use?**
Ardsley Partners' most recent Form ADV filing (Schedule D, Section 5.K(3)) lists Morgan Stanley & Co. LLC as a custodian holding 10% or more of its separately managed account assets.

**Does Ardsley Partners report any disciplinary disclosures?**
Reports no disclosure items on Form ADV Item 11. The detail of any item is on the firm's SEC record: https://adviserinfo.sec.gov/firm/summary/301116

**What changed in Ardsley Partners' recent Form ADV filings?**
In the March 2026 filing data: Employees performing advisory functions went from 9 to 7. Regulatory assets under management went from $1,143,814,787 to $1,635,701,621 (+43%).

## From the Form ADV filing

### Compensation (Item 5.E)
- A percentage of assets under your management
- Performance-based fees

### Custodians (Schedule D, Section 5.K(3))
- Morgan Stanley & Co. LLC

Custodians holding 10% or more of the firm's separately managed account assets, as filed on Form ADV (Schedule D, Section 5.K(3)). A custodian holds client assets; it does not endorse or supervise the firm. AdvisorCensus has no relationship with any custodian.

### Regulatory assets under management (Item 5.F)
- Total: $1,635,701,621
- Discretionary: $1,635,701,621
- Non-discretionary: $0

### Clients (Item 5.D)

| Client type | Clients | Assets |
| --- | --- | --- |
| Pooled investment vehicles (other than investment companies and business development companies) | 9 | $1,426,203,216 |
| Other | 2 | $209,498,405 |

### Advisory services (Item 5.G)
- Portfolio management for pooled investment vehicles (other than investment companies)
- Portfolio management for businesses (other than small businesses) or institutional clients

### Firm details
- Registered since: 2019 (7 years)
- Employees: 11 total, 7 performing advisory functions
- Wrap fee program participation: No
- States registered or notice-filed: CT
- Disclosures (Item 11): Reports no disclosure items on Form ADV Item 11.

### Websites listed on Form ADV (Item 1.I)
- ardsley.com

## Assets and staff over time

| Data period | Regulatory assets under management | Employees | Filing dated |
| --- | --- | --- | --- |
| October 2021 | $1,197,794,786 | 12 | March 10, 2021 |
| October 2022 | $851,898,478 | 12 | March 2, 2022 |
| October 2023 | $789,305,344 | 12 | June 7, 2023 |
| October 2024 | $869,605,434 | 13 | January 30, 2024 |
| October 2025 | $1,143,814,787 | 14 | May 14, 2025 |
| October 2026 | $1,635,701,621 | 11 | May 6, 2026 |

Regulatory assets under management: $1,197,794,786 in the October 2021 data and $1,635,701,621 in the October 2026 data, up 37%.
Total employees: 12 in October 2021 and 11 in October 2026.

## Changes in the filing (last 12 months)

### March 2026
- Employees performing advisory functions went from 9 to 7.
- Regulatory assets under management went from $1,143,814,787 to $1,635,701,621 (+43%).

## Source

Form ADV as filed, October 2026. Values appear as filed. Cite as: AdvisorCensus. Ardsley Partners (CRD 301116): Form ADV filing data as of October 2026.