Seaport Therapeutics (SPTX) insider Steven M. Paul reports 6.3% stake

Rhea-AI Filing Summary

Seaport Therapeutics, Inc. reports that Steven M. Paul beneficially owns 3,516,718 shares of its Voting Common Stock as of June 30, 2026. This amount represents 6.3% of the 53,530,550 shares of Common Stock stated to be outstanding on that date.

The position consists of 863,031 shares held of record by Steven M. Paul and 2,653,687 shares underlying stock options that are exercisable within 60 days of June 30, 2026. He has sole voting and dispositive power over all 3,516,718 shares and no shared voting or dispositive power.

Key Figures

Beneficial ownership: 3,516,718 shares Ownership percentage: 6.3% Shares outstanding: 53,530,550 shares +3 more

6 metrics

Beneficial ownership 3,516,718 shares Shares of Voting Common Stock beneficially owned by Steven M. Paul as of June 30, 2026

Ownership percentage 6.3% Percent of Seaport Therapeutics Voting Common Stock class owned by Steven M. Paul

Shares outstanding 53,530,550 shares Voting Common Stock outstanding as of June 30, 2026, as provided by Seaport Therapeutics

Shares held of record 863,031 shares Common Stock held of record directly by Steven M. Paul

Options exercisable within 60 days 2,653,687 shares Shares underlying stock options exercisable within 60 days of June 30, 2026

Par value per share $0.0001 per share Par value of Seaport Therapeutics Voting Common Stock

Key Terms

beneficial owner, sole voting power, sole dispositive power, stock options exercisable within 60 days, +1 more

5 terms

beneficial owner financial

"The Reporting Person is deemed to be the beneficial owner of 3,516,718 shares"

A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.

sole voting power financial

"Sole Voting Power 3,516,718.00 6 | Shared Voting Power 0.00"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

sole dispositive power financial

"Sole Dispositive Power 3,516,718.00 8 | Shared Dispositive Power 0.00"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

stock options exercisable within 60 days financial

"2,653,687 shares of Common Stock subject to stock options exercisable within 60 days"

Voting Common Stock financial

"Title of class of securities: Voting Common Stock, $0.0001 par value per share"

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/05/2026 - 06:05 AM Accepted by SEC EDGAR 08/05/2026 - 06:01 AM Learn about SEC filing dates

FAQ

How many SPTX shares does Steven M. Paul beneficially own according to this Schedule 13G?

According to the filing, Steven M. Paul beneficially owns 3,516,718 shares of Seaport Therapeutics Voting Common Stock. This total includes both shares held of record and shares underlying stock options exercisable within 60 days of June 30, 2026.

What percentage of Seaport Therapeutics (SPTX) does Steven M. Paul own?

The filing states that Steven M. Paul owns 6.3% of the outstanding Voting Common Stock of Seaport Therapeutics, Inc. This percentage is based on 53,530,550 shares of Common Stock outstanding as of June 30, 2026.

How is Steven M. Paul’s SPTX ownership split between shares and options?

Steven M. Paul’s beneficial ownership includes 863,031 shares of Common Stock held of record and 2,653,687 shares issuable upon exercise of stock options that are exercisable within 60 days of June 30, 2026.

Does Steven M. Paul share voting or dispositive power over his SPTX shares?

No. The filing reports that Steven M. Paul has sole voting power over 3,516,718 shares and sole dispositive power over 3,516,718 shares, with no shared voting or dispositive power over any Seaport Therapeutics shares.

What is the reference date for the ownership figures in this SPTX Schedule 13G?

All ownership figures are stated as of June 30, 2026. The 6.3% ownership calculation is based on 53,530,550 shares of Seaport Therapeutics Common Stock outstanding on that date, as provided by the company.

What class of Seaport Therapeutics (SPTX) securities is reported in this Schedule 13G?

The Schedule 13G covers Voting Common Stock of Seaport Therapeutics, Inc., with a par value of $0.0001 per share. The security is identified with CUSIP number 81221K108 in the filing.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

Seaport Therapeutics, Inc.

(Name of Issuer)

Voting Common Stock, $0.0001 par value per share

(Title of Class of Securities)

81221K108

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 81221K108

1

Names of Reporting Persons

PAUL STEVEN M

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 3,516,718.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 3,516,718.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,516,718.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

6.3 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Seaport Therapeutics, Inc.
(b)	Address of issuer's principal executive offices: 101 Seaport Blvd., Floor 12, Boston, MA 02210
Item 2.
(a)	Name of person filing: This statement is filed on behalf of Steven M. Paul (the "Reporting Person").
(b)	Address or principal business office or, if none, residence: The address of the principal business office of the Reporting Person is 101 Seaport Blvd., Floor 12, Boston, MA 02210.
(c)	Citizenship: The Reporting Person is a citizen of the United States.
(d)	Title of class of securities: Voting Common Stock, $0.0001 par value per share
(e)	CUSIP Number(s): 81221K108
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: The ownership information below represents beneficial ownership of Voting Common Stock, par value $0.0001 per share ("Common Stock") of the Issuer as of June 30, 2026, based upon 53,530,550 shares of Common Stock outstanding as of June 30, 2026, as provided by the Issuer. The Reporting Person is deemed to be the beneficial owner of 3,516,718 shares of Common Stock, consisting of (i) 863,031 shares of Common Stock held of record by the Reporting Person and (ii) 2,653,687 shares of Common Stock subject to stock options exercisable within 60 days of June 30, 2026 by the Reporting Person.
(b)	Percent of class: 6.3 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 3,516,718
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 3,516,718
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.	Certifications:
	Not Applicable

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

PAUL STEVEN M

Signature:	/s/ Steven M. Paul
Name/Title:	Steven M. Paul
Date:	08/05/2026