AdvisorCensus / Financial advisors / New York / New York / Third Harbor
Third Harbor
Filed as THIRD HARBOR · Legal name Third Harbor Partners L.P.
Third Harbor is an SEC-registered investment advisory firm in Cold Spring Harbor, NY, registered since 2026, with no regulatory assets under management reported in its Form ADV filing dated August 11, 2026.
Quick answers
From the filingHow is Third Harbor compensated?
On its Form ADV (Item 5.E, October 2026), Third Harbor reports these compensation arrangements: a percentage of assets under its management; performance-based fees.
Where is Third Harbor located?
Third Harbor's principal office is in Cold Spring Harbor, NY, according to its Form ADV.
Is Third Harbor registered with the SEC or a state?
Third Harbor is an SEC-registered investment advisory firm, registered since 2026. Status as filed: 120-Day Approval. CRD 343219.
Does Third Harbor 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/343219
What changed in Third Harbor's recent Form ADV filings?
In the September 2026 filing data: Changed its legal name from Third Harbor Management L.P. to Third Harbor Partners L.P..
From the Form ADV filing
Every figure below is as the firm filed it with regulators, as of October 2026.
How the firm is compensated
Item 5.E- A percentage of assets under your management
- Performance-based fees
Item 5.E lists how the firm is compensated for its advice; Items 5.B, 6.A, and 7.A show whether its people or related companies can also earn commissions. Percentage of assets, fixed, hourly, subscription, and performance-based fees come from clients (a performance-based fee depends on investment results); commissions come with a sale or a trade, often from the company behind the product. How fees, commissions, and other arrangements differ
Fees and minimums
Form ADV Part 2ASee the firm's brochure (dated August 11, 2026) for its fees and any account minimum, on the SEC's IAPD site.
Regulatory assets under management
Item 5.FNot reported.
A measure of scale, not skill or returns. Discretionary means the firm decides trades; non-discretionary means clients approve each one. What assets under management means
Who the firm serves
Item 5.DNot reported.
A firm with no individual clients is an institutional manager even if it manages billions; the mix tells you whom the practice is built around.
Advisory services
Item 5.G- Portfolio management for pooled investment vehicles (other than investment companies)
Registration and firm details
Items 1, 2, 5- Legal name
- Third Harbor Partners L.P.
- Registration
- SEC-registered investment adviser. Status as filed: 120-Day Approval.
- Registered since
- 2026 (0 years)
- Employees
- Total: 3. Performing investment advisory functions: 3.
- Wrap fee program participation
- No.
- States registered or notice-filed
- Not reported.
SEC-registered investment advisers are examined by the SEC. SEC, state, and exempt registration
Disclosures
Item 11None Reports no disclosure items on Form ADV Item 11. View on IAPD.
Item 11 asks about criminal, regulatory, and civil events involving the firm and its advisory personnel. The detail of each yes answer is on the IAPD record. Reading a firm's disclosures
Changes in the filing
Last 12 months- September 2026
- Changed its legal name from Third Harbor Management L.P. to Third Harbor Partners L.P..
- August 2026
- Newly registered with the SEC.
Compared month to month from the SEC's monthly adviser data and the state compilation feed. Owners and control persons are summarized, never named.
Websites listed on Form ADV
Item 1.INot reported.
Source: Form ADV, as of October 2026. Values appear as filed; a value the firm did not report is shown as "Not reported."
Cite this page
AdvisorCensus. Third Harbor (CRD 343219): Form ADV filing data as of October 2026. https://advisorcensus.com/firm/third-harbor-cold-spring-harbor-ny-343219