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Director Sandra Peterson reports Seaport Therapeutics (SPTX) stock option holdings

(Neutral)
(Neutral)
Form Type
3

Rhea-AI Filing Summary

Seaport Therapeutics director Sandra E. Peterson reported her initial holdings of stock options in Seaport Therapeutics, Inc. The filing lists two option grants to buy Common Stock: one covering 12,258 underlying shares at an exercise price of $10.31, and another covering 77,042 underlying shares at $7.39.

For the 12,258-share option, one-third of the underlying shares vested on December 2, 2025, with the rest vesting in 24 equal monthly installments, subject to her continued service. The 77,042-share option is scheduled to vest and become exercisable on February 24, 2027, also subject to continued service, with expiration dates in 2036 and 2034 respectively.

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Insider PETERSON SANDRA E
Role Director
Type Security Shares Price Value
holding Stock Option (Right to Buy) -- -- --
holding Stock Option (Right to Buy) -- -- --
Holdings After Transaction: Stock Option (Right to Buy) — 77,042 shares (Direct)
Footnotes (1)
  1. 1/3rd of the shares underlying this option vested and became exercisable on December 2, 2025, with the remaining shares vesting in twenty-four (24) equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date. The shares underlying this option shall vest and become exercisable on February 24, 2027, subject to the Reporting Person's continued service on such vesting date.
Option underlying shares 1 12,258 shares Underlying Common Stock for one stock option holding
Exercise price 1 $10.31 per share Exercise price of 12,258-share stock option
Option underlying shares 2 77,042 shares Underlying Common Stock for second stock option holding
Exercise price 2 $7.39 per share Exercise price of 77,042-share stock option
Expiration date 1 February 23, 2036 Expiration of 12,258-share option
Expiration date 2 December 28, 2034 Expiration of 77,042-share option
Initial derivative holdings entries 2 option positions Holding entries listed in Form 3 transaction summary
Stock Option (Right to Buy) financial
"security_title: Stock Option (Right to Buy)"
exercise price financial
"conversion_or_exercise_price: 10.3100 and 7.3900"
The exercise price is the fixed amount at which you can buy or sell an asset, like a stock, when using an options contract. It matters because it helps determine whether exercising the option will be profitable or not, depending on the current market price. Think of it as the set price you agree on today to buy or sell later.
expiration date financial
"expiration_date: 2036-02-23T00:00:00.000Z and 2034-12-28T00:00:00.000Z"
The expiration date is the deadline after which a financial contract, such as an option or a futures agreement, is no longer valid or can be exercised. It matters to investors because it determines the timeframe during which they can take action or benefit from the contract, similar to how a coupon or a food item has a limited period of usefulness. Once the expiration date passes, the contract loses its value or ability to be used.
vest financial
"1/3rd of the shares underlying this option vested and became exercisable"
A vest is the process by which an employee earns the right to receive certain benefits or ownership interests, such as stock or retirement funds, over time. It’s similar to earning a reward gradually, ensuring that the benefit becomes fully yours only after a set period or meeting specific conditions. This makes it important for investors because it determines when they can actually claim or use those benefits.
underlying security financial
"underlying_security_title: Common Stock"

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

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FAQ

What does Sandra E. Peterson’s Form 3 for Seaport Therapeutics (SPTX) show?

The Form 3 shows initial stock option holdings for director Sandra E. Peterson. She holds options over 12,258 shares at $10.31 and 77,042 shares at $7.39, each with specific vesting schedules and long-dated expiration terms.

Are there any stock purchases or sales in Sandra Peterson’s Seaport Therapeutics (SPTX) Form 3?

The filing reports holdings only, with no indicated stock purchases or sales. It lists two stock option positions, their exercise prices, vesting conditions, and expiration dates, serving as a baseline disclosure of her derivative ownership in Seaport Therapeutics.

What are the vesting terms of Sandra Peterson’s 12,258-share option in SPTX?

For the 12,258-share option, one-third vested on December 2, 2025. The remaining shares vest in twenty-four equal monthly installments thereafter, conditioned on her continued service with Seaport Therapeutics on each vesting date.

When do Sandra Peterson’s Seaport Therapeutics stock options expire?

Her 12,258-share option at $10.31 per share expires on February 23, 2036. The 77,042-share option at $7.39 per share expires on December 28, 2034, providing long-term potential exercisability if vesting and service conditions are met.

How many Seaport Therapeutics (SPTX) shares underlie Sandra Peterson’s reported options?

The Form 3 lists options over 89,300 underlying shares of Common Stock in total. This consists of 12,258 underlying shares at an exercise price of $10.31 and 77,042 underlying shares at $7.39, all held directly.
SEC Form 3
FORM 3UNITED 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*
PETERSON SANDRA E

(Last)(First)(Middle)
SEAPORT THERAPEUTICS, INC.
101 SEAPORT BLVD., FLOOR 12

(Street)
BOSTON MASSACHUSETTS 02210

(City)(State)(Zip)

UNITED STATES

(Country)
2. Date of Event Requiring Statement (Month/Day/Year)
04/30/2026
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)
XDirector10% Owner
Officer (give title below)Other (specify below)
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
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)
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 ExercisableExpiration DateTitleAmount or Number of Shares
Stock Option (Right to Buy) (1)12/28/2034Common Stock77,042$7.39D
Stock Option (Right to Buy) (2)02/23/2036Common Stock12,258$10.31D
Explanation of Responses:
1. 1/3rd of the shares underlying this option vested and became exercisable on December 2, 2025, with the remaining shares vesting in twenty-four (24) equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.
2. The shares underlying this option shall vest and become exercisable on February 24, 2027, subject to the Reporting Person's continued service on such vesting date.
Remarks:
Exhibit 24 - Power of Attorney
/s/ Lana Gladstein, Attorney-in-Fact04/30/2026
** Signature of Reporting PersonDate
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)