General Atlantic (SPTX) funds report 6.1M Seaport Therapeutics shares on Form 3

Rhea-AI Filing Summary

Seaport Therapeutics, Inc. filed an initial Form 3 showing that General Atlantic–affiliated funds hold 6,101,582 shares of its Common Stock. This amount includes 3,351,582 shares issuable upon conversion of Series B preferred stock. The holdings are reported as indirect, through multiple partnerships and investment vehicles described in the footnotes. A six-member Partnership Committee ultimately controls key general partners, and each member disclaims beneficial ownership of the shares except to the extent of any pecuniary interest.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider General Atlantic (SP), L.P., GENERAL ATLANTIC, L.P., GENERAL ATLANTIC GENPAR, L.P., General Atlantic Partners 100, L.P., GAP COINVESTMENTS III, LLC, GAP COINVESTMENTS IV, LLC, GAP Coinvestments V, LLC, GENERAL ATLANTIC GENPAR (BERMUDA), L.P., General Atlantic (SPV) GP, LLC, GAP (Bermuda) L.P.

Role null | null | null | null | null | null | null | null | null | null

Type	Security	Shares	Price	Value
holding	Common Stock, par value $0.0001 per share ("Common Stock")	--	--	--

Holdings After Transaction: Common Stock, par value $0.0001 per share ("Common Stock") — 6,101,582 shares (Indirect, See footnote)

Footnotes (1)

1. Reflects 6,101,582 shares of Common Stock held by General Atlantic (SP), L.P., or General Atlantic SP, including 3,351,582 shares of Common Stock issuable upon conversion of Series B preferred stock. The limited partners that share beneficial ownership of the shares held by General Atlantic SP, or the GA Funds, are General Atlantic Partners 100, L.P., or GAP 100, General Atlantic Partners (Lux), SCSp, or GAP Lux, GAP Coinvestments III, LLC, or GAPCO III, GAP Coinvestments IV, LLC, or GAPCO IV, GAP Coinvestments V, LLC, or GAPCO V, and GAP Coinvestments CDA, L.P., or GAPCO CDA. The general partner of GAP 100 is General Atlantic GenPar, L.P., (Cont'd in FN2) (Cont'd from FN1) or GA GenPar. General Atlantic, L.P., or GA LP, which is controlled by the Partnership Committee of GASC MGP, LLC (the "Partnership Committee"), is the managing member of GAPCO III, GAPCO IV and GAPCO V, the general partner of GAPCO CDA and GA GenPar, and the sole member of General Atlantic (SPV) GP, LLC, or GA SPV. The general partner of General Atlantic SP is GA SPV. The general partner of GAP Lux is General Atlantic GenPar, (Lux) SCSp, or GA GenPar Lux, and the general partner of GA GenPar Lux is General Atlantic (Lux) S.a r.l., or GA Lux. The sole shareholder of GA Lux is General Atlantic GenPar (Bermuda), L.P., or GenPar Bermuda. GAP (Bermuda) L.P., or GAP Bermuda, which is ultimately controlled by the Partnership Committee, is the general partner of GenPar Bermuda. (Cont'd in FN3) (Cont'd from FN2) There are six members of the Partnership Committee. Each of the members of the Partnership Committee disclaims ownership of the shares except to the extent that he or she has a pecuniary interest therein.

Key Figures

Beneficial ownership: 6,101,582 shares Conversion shares: 3,351,582 shares

2 metrics

Beneficial ownership 6,101,582 shares Common Stock beneficially owned by General Atlantic (SP), L.P.

Conversion shares 3,351,582 shares Common Stock issuable upon conversion of Series B preferred stock

Key Terms

beneficial ownership, Series B preferred stock, pecuniary interest, Partnership Committee

4 terms

beneficial ownership financial

"The limited partners that share beneficial ownership of the shares held by General Atlantic SP, or the GA Funds, are General Atlantic Partners 100, L.P."

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

Series B preferred stock financial

"including 3,351,582 shares of Common Stock issuable upon conversion of Series B preferred stock."

Series B preferred stock is a type of ownership share issued by a company that offers certain advantages over common stock, such as priority in receiving dividends or assets if the company is sold or liquidated. It is typically issued after an initial round of funding, making it a way for investors to support a company's growth while gaining some protections and benefits. This stock matters to investors because it often provides a more secure investment position with potential for future growth.

pecuniary interest financial

"Each of the members of the Partnership Committee disclaims ownership of the shares except to the extent that he or she has a pecuniary interest therein."

Partnership Committee financial

"GAP (Bermuda) L.P., or GAP Bermuda, which is ultimately controlled by the Partnership Committee, is the general partner of GenPar Bermuda."

Understanding Insider Trading Forms →

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

General Atlantic (SP), L.P.

(Last) (First) (Middle)

C/O GENERAL ATLANTIC SERVICE CO., L.P.

55 EAST 52ND STREET, 33RD FLOOR

(Street)

NEW YORK NEW YORK 10055

(City) (State) (Zip)

UNITED STATES

(Country)

2. Date of Event Requiring Statement (Month/Day/Year)
05/04/2026

3. Issuer Name and Ticker or Trading Symbol
Seaport Therapeutics, Inc. [ SPTX ]

3a. Foreign Trading Symbol

5. If Amendment, Date of Original Filed (Month/Day/Year)

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock, par value $0.0001 per share ("Common Stock")	6,101,582	I	See footnote(1)(2)(3)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person^*

General Atlantic (SP), L.P.

(Last) (First) (Middle)

C/O GENERAL ATLANTIC SERVICE CO., L.P.

55 EAST 52ND STREET, 33RD FLOOR

(Street)

NEW YORK NEW YORK 10055

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

GENERAL ATLANTIC, L.P.

(Last) (First) (Middle)

C/O GENERAL ATLANTIC SERVICE CO., L.P.

55 EAST 52ND STREET, 33RD FLOOR

(Street)

NEW YORK NEW YORK 10055

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

GENERAL ATLANTIC GENPAR, L.P.

(Last) (First) (Middle)

C/O GENERAL ATLANTIC SERVICE CO., L.P.

55 EAST 52ND STREET, 33RD FLOOR

(Street)

NEW YORK NEW YORK 10055

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

General Atlantic Partners 100, L.P.

(Last) (First) (Middle)

C/O GENERAL ATLANTIC SERVICE CO., L.P.

55 EAST 52ND STREET, 33RD FLOOR

(Street)

NEW YORK NEW YORK 10055

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

GAP COINVESTMENTS III, LLC

(Last) (First) (Middle)

C/O GENERAL ATLANTIC SERVICE CO., L.P.

55 EAST 52ND STREET, 33RD FLOOR

(Street)

NEW YORK NEW YORK 10055

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

GAP COINVESTMENTS IV, LLC

(Last) (First) (Middle)

C/O GENERAL ATLANTIC SERVICE CO., L.P.

55 EAST 52ND STREET, 33RD FLOOR

(Street)

NEW YORK NEW YORK 10055

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

GAP Coinvestments V, LLC

(Last) (First) (Middle)

C/O GENERAL ATLANTIC SERVICE CO., L.P.

55 EAST 52ND STREET, 33RD FLOOR

(Street)

NEW YORK NEW YORK 10055

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

GENERAL ATLANTIC GENPAR (BERMUDA), L.P.

(Last) (First) (Middle)

C/O CONYERS CLIENT SERVICES LIMITED,

CLARENDON HOUSE, 2 CHURCH STREET

(Street)

HAMILTON HM 11

(City) (State) (Zip)

BERMUDA

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

General Atlantic (SPV) GP, LLC

(Last) (First) (Middle)

C/O GENERAL ATLANTIC SERVICE CO., L.P.

55 EAST 52ND STREET, 33RD FLOOR

(Street)

NEW YORK NEW YORK 10055

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

GAP (Bermuda) L.P.

(Last) (First) (Middle)

C/O CONYERS CLIENT SERVICES LIMITED,

CLARENDON HOUSE, 2 CHURCH STREET

(Street)

HAMILTON HM 11

(City) (State) (Zip)

BERMUDA

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. Reflects 6,101,582 shares of Common Stock held by General Atlantic (SP), L.P., or General Atlantic SP, including 3,351,582 shares of Common Stock issuable upon conversion of Series B preferred stock. The limited partners that share beneficial ownership of the shares held by General Atlantic SP, or the GA Funds, are General Atlantic Partners 100, L.P., or GAP 100, General Atlantic Partners (Lux), SCSp, or GAP Lux, GAP Coinvestments III, LLC, or GAPCO III, GAP Coinvestments IV, LLC, or GAPCO IV, GAP Coinvestments V, LLC, or GAPCO V, and GAP Coinvestments CDA, L.P., or GAPCO CDA. The general partner of GAP 100 is General Atlantic GenPar, L.P., (Cont'd in FN2)

2. (Cont'd from FN1) or GA GenPar. General Atlantic, L.P., or GA LP, which is controlled by the Partnership Committee of GASC MGP, LLC (the "Partnership Committee"), is the managing member of GAPCO III, GAPCO IV and GAPCO V, the general partner of GAPCO CDA and GA GenPar, and the sole member of General Atlantic (SPV) GP, LLC, or GA SPV. The general partner of General Atlantic SP is GA SPV. The general partner of GAP Lux is General Atlantic GenPar, (Lux) SCSp, or GA GenPar Lux, and the general partner of GA GenPar Lux is General Atlantic (Lux) S.a r.l., or GA Lux. The sole shareholder of GA Lux is General Atlantic GenPar (Bermuda), L.P., or GenPar Bermuda. GAP (Bermuda) L.P., or GAP Bermuda, which is ultimately controlled by the Partnership Committee, is the general partner of GenPar Bermuda. (Cont'd in FN3)

3. (Cont'd from FN2) There are six members of the Partnership Committee. Each of the members of the Partnership Committee disclaims ownership of the shares except to the extent that he or she has a pecuniary interest therein.

Remarks:

GA LP, GAP Bermuda, GA Lux, GA GenPar Lux, GA SPV, and the GA Funds may be deemed to be members of a "group" for the purposes of the Securities Exchange Act of 1934. Each reporting person disclaims beneficial ownership of any securities deemed to be owned by the group that are not directly owned by the reporting person. This report shall not be deemed an admission that the reporting persons are a member of a group or the beneficial owner of any securities not directly owned by the reporting person. Each of the reporting persons is a director-by-deputization solely for purposes of Section 16 of the Exchange Act. // Form 1 of 2

	/s/ Michael Gosk	05/06/2026
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	/s/ Michael Gosk	05/06/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 3: SEC 1473 (03-26)

FAQ

What does General Atlantic report owning in Seaport Therapeutics (SPTX) on this Form 3?

General Atlantic–affiliated funds report beneficial ownership of 6,101,582 Seaport Therapeutics common shares, including 3,351,582 shares issuable upon conversion of Series B preferred stock, all held indirectly through fund and partnership structures.

How many SPTX shares are tied to preferred stock in General Atlantic’s Form 3?

The Form 3 states that 3,351,582 SPTX common shares are issuable upon conversion of Series B preferred stock. These conversion shares form part of the total 6,101,582 common shares reported as beneficially owned.

Are General Atlantic’s Seaport Therapeutics (SPTX) holdings direct or indirect?

The filing reports indirect beneficial ownership of Seaport Therapeutics shares. The 6,101,582 common shares are held through General Atlantic (SP), L.P. and related funds and partnerships, rather than directly by individual committee members.

Who ultimately controls the General Atlantic entities holding SPTX shares?

The Form 3 explains that key General Atlantic entities are ultimately controlled by a six-member Partnership Committee of GASC MGP, LLC. Each committee member disclaims ownership of the shares except for any personal pecuniary interest.

Does this General Atlantic Form 3 for SPTX show any recent share purchases or sales?

No specific purchase or sale is reported; the entry reflects a holding of 6,101,582 Seaport Therapeutics common shares. It is an initial statement of beneficial ownership rather than a transaction report.