As of November 6, 2026, Seaport Therapeutics, Inc. is a publicly traded company (Nasdaq: SPTX). The largest holder reporting an active stake on Schedule 13D is ARCH Venture Fund XII, L.P., at 11.9%. No bankruptcy or receivership appears in its SEC Form 8-K filings (Schedule 13D, May 6, 2026).
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Is Seaport Therapeutics, Inc. a real, registered company?
- Seaport Therapeutics, Inc. files with the SEC under CIK 2042347 (its SEC filings).
- Its shares are listed under the ticker SPTX on Nasdaq (SEC company record).
- Incorporated in Delaware; business address in Boston, Massachusetts, as its SEC filings state.
- Court and bankruptcy records: see Before you sign or pay below.
Before you sign or pay
- Court and bankruptcy: No federal court case or bankruptcy filing found under Seaport Therapeutics, Inc. in our court records and SEC 8-K records (as of 2026-11-06).
- Ownership: 5%+ holders are reported on Schedule 13D or 13G; the latest names PureTech Health plc (filed 2026-08-14).
Who are Seaport Therapeutics, Inc.'s owners and officers?
Seaport Therapeutics, Inc.: incorporated in Delaware; business address in Boston, Massachusetts; industry Pharmaceutical Preparations (Schedule 13G, 2026-08-14).
Officers and directors, each with the role and the filing that names them:
- : Executive Officer, Director (Form D, 2024-10-31)
- : Executive Officer (Form D, 2024-10-31)
- : Executive Officer (Form D, 2024-10-31)
- : Executive Officer (Form D, 2024-10-31)
- : Executive Officer (Form D, 2024-10-31)
- : Director (Form D, 2024-10-31)
- : Director (Form D, 2024-10-31)
- : Director (Form D, 2024-10-31)
- : Director (Form D, 2024-10-31)
- : Director (Form D, 2024-10-31)
- : Director (Form D, 2024-10-31)
- : Director (Form D, 2024-10-31)
| Report | Holder | Share |
|---|---|---|
| Schedule 13G, 2026-08-14 | Puretech Health PLC | 31.2% |
| Schedule 13G, 2026-08-05 | Paul Steven M | 6.3% |
| Schedule 13G, 2026-08-05 | Zohar Daphne | 9.1% |
| Schedule 13D, 2026-05-11 | General Atlantic, L.P. | 11.5% |
| Schedule 13G, 2026-05-11 | The Goldman Sachs Group, Inc. | 5.5% |
| Schedule 13D, 2026-05-06 | Arch Venture Fund Xii, L.P. | 11.9% |
Questions about who owns Seaport Therapeutics, Inc.
Who owns Seaport Therapeutics, Inc.?
On this page, 6 holders' latest ownership filings report 5% or more of Seaport Therapeutics, Inc.: Puretech Health PLC (31.2%, Schedule 13G, filed 2026-08-14), Arch Venture Fund Xii, L.P. (11.9%, Schedule 13D, filed 2026-05-06), General Atlantic, L.P. (11.5%, Schedule 13D, filed 2026-05-11), Zohar Daphne (9.1%, Schedule 13G, filed 2026-08-05) and Paul Steven M (6.3%, Schedule 13G, filed 2026-08-05); 1 more is listed above.
Who are the largest shareholders of Seaport Therapeutics, Inc.?
By the share each holder's latest filing reports, the largest holders of Seaport Therapeutics, Inc. on this page are Puretech Health PLC (31.2%), Arch Venture Fund Xii, L.P. (11.9%) and General Atlantic, L.P. (11.5%).
When did Puretech Health PLC buy into Seaport Therapeutics, Inc.?
The filings give report dates, not purchase dates. The earliest filing from Puretech Health PLC on this page is the Schedule 13G, filed 2026-08-14, reporting 31.2%.
Is this an audit or a full list?
Neither. The ownership list on this page covers only Schedule 13D and 13G filings, which holders make once they own 5% or more of a class of shares (an amendment can report a stake that has since fallen below 5%); 6 such filings are shown here. It is not an audit and not a full cap table: holders who never reached 5% are not listed, and a stake can change after its latest filing.
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What the Full Report on Seaport Therapeutics, Inc. covers
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Which insiders own Seaport Therapeutics, Inc. shares?
Directors, officers and holders of 10% or more report their shares on Forms 3, 4 and 5. Each line is the latest such report, largest holding first.
- , Inc., a 10% owner: 16,685,013 shares (31.2% of shares outstanding), held indirectly (the form names the holder only in its footnotes), on a joint filing (Form 4, 2026-05-06).
- PureTech Health plc, a 10% owner: 16,685,013 shares (31.2% of shares outstanding), held indirectly (the form names the holder only in its footnotes), on a joint filing (Form 4, 2026-05-06).
- ARCH Venture Partners XII, LLC, a 10% owner: 6,294,951 shares (11.8% of shares outstanding), held indirectly through By ARCH Venture Fund XII, L.P., on a joint filing (Form 4, 2026-05-04).
- ARCH Venture Partners XII, L.P., a 10% owner: 6,294,951 shares (11.8% of shares outstanding), held indirectly through By ARCH Venture Fund XII, L.P., on a joint filing (Form 4, 2026-05-04).
- , a 10% owner: 6,294,951 shares (11.8% of shares outstanding), held indirectly through By ARCH Venture Fund XII, L.P., on a joint filing (Form 4, 2026-05-04).
Shares outstanding: 53,530,550 as of 2026-10-27, from the company's latest SEC cover page.
How much has Seaport Therapeutics, Inc. raised?
| Filed | Sold | Offered |
|---|---|---|
| Form D, 2024-10-31 | $225.90M | $226M |
Latest IPO step: Seaport Therapeutics, Inc. filed its final IPO prospectus, ticker SPTX (424B4, 2026-05-01).
IPO filings: 424B4, 2026-05-01, S-1/A, 2026-04-27, S-1, 2026-04-10; ticker SPTX on Nasdaq Global Select Market.
Keep reading
More on Seaport Therapeutics, Inc. and the records around it.
Seaport Therapeutics, Inc. elsewhere on the record
- 5%+ stake filings Aug 2026
Companies that share a holder
- ARCH Venture Fund XII, L.P. also filed stake reports on 5 other companies: City Therapeutics, Inc. (Oct 2026), Parabilis Medicines, Inc. (Aug 2026), Neumora Therapeutics, Inc. (Apr 2026)
- General Atlantic, L.P. also filed stake reports on 10 other companies: Korsana Biosciences, Inc. (Sep 2026), dLocal Ltd (Aug 2026), Pharvaris N.V. (Aug 2026)
- THE GOLDMAN SACHS GROUP, INC. also filed stake reports on 173 other companies: AEON ACQUISITION I CORP. (Nov 2026), ALPEX ACQUISITION CORPORATION (Nov 2026), ARCHIMEDES TECH SPAC PARTNERS II CO. (Nov 2026)
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https://mentionfox.com/who-owns/seaport-therapeutics