Stamatios Tsantanis reports 9.62% stake in Seanergy Maritime (SHIP)

Rhea-AI Filing Summary

Seanergy Maritime Holdings Corp. executive Stamatios Tsantanis reports beneficial ownership of 2,084,403 shares of common stock, representing about 9.62% of the class based on 21,668,198 shares outstanding as of March 27, 2026. He holds sole voting and dispositive power over these shares.

During the period, 50 call options on 5,000 shares with an $8.00 exercise price expired unexercised, and another 50 call options to buy 5,000 shares at $8.00 per share were exercised. He then sold 1,000 shares at an average price of $8.22 per share. In his role as an executive officer, he received 196,000 shares on March 12, 2025 and 198,000 shares on March 6, 2026 under the 2011 Equity Incentive Plan, with portions vesting between September 2026 and September 2027.

Key Figures

Beneficial ownership: 2,084,403 shares Ownership percentage: 9.62% Shares outstanding: 21,668,198 shares +5 more

8 metrics

Beneficial ownership 2,084,403 shares Common Stock beneficially owned by Stamatios Tsantanis

Ownership percentage 9.62% Percent of Seanergy Maritime common stock class owned

Shares outstanding 21,668,198 shares Common Stock outstanding as of March 27, 2026

Options expired 5,000 shares at $8.00 Call options expired unexercised on July 18, 2025

Options exercised 5,000 shares at $8.00 Call options exercised on October 17, 2025

Shares sold 1,000 shares at $8.22 Sale of Common Stock on October 23, 2025

Equity grant 2025 196,000 shares Shares issued on March 12, 2025 under 2011 Equity Incentive Plan

Equity grant 2026 198,000 shares Shares issued on March 6, 2026 under 2011 Equity Incentive Plan

Key Terms

beneficially owned, Schedule 13D, Equity Incentive Plan, call options, +1 more

5 terms

beneficially owned financial

"Aggregate number and percentage of class beneficially owned: 2,084,403 shares, or approximately 9.62% of the class"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

Schedule 13D regulatory

"If the filing person has previously filed a statement on Schedule 13G to report the acquisition"

A Schedule 13D is a legal document that investors file with regulators when they buy a large enough stake in a company to potentially influence its management or decisions. It provides details about the investor’s intention, ownership stake, and plans, helping other investors understand who is gaining control and what their motives might be.

Equity Incentive Plan financial

"in accordance with the Issuer's 2011 Equity Incentive Plan, as amended"

An equity incentive plan is a program that gives employees, executives or directors the right to receive company stock or options to buy stock as part of their pay. Think of it as offering slices of future company profit to motivate people to boost long‑term performance; for investors it matters because it can align employee goals with shareholder value but also increases the number of shares outstanding, which can dilute existing ownership.

call options financial

"50 call options held by the Reporting Person to purchase 5,000 shares of Common Stock"

A call option is a contract that gives its buyer the right, but not the obligation, to buy a specific number of shares at a predetermined price within a set time. Think of it like a refundable reservation to purchase a stock later at today’s agreed price: investors use calls to profit from expected price rises with smaller upfront cost than buying the stock outright, or to hedge and manage exposure, while the most they can lose is the amount paid for the contract.

vesting provisions financial

"These shares of Common Stock are subject to vesting provisions, as follows"

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 3)

Seanergy Maritime Holdings Corp.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

Y73760400

(CUSIP Number)

Stamatios Tsantanis
154 Vouliagmenis Avenue,,
Glyfada, J3, 166 74
30 213 01 81 507

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

03/06/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): Y73760400

1

Name of reporting person

Tsantanis Stamatios

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

GREECE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 2,084,403.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 2,084,403.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

2,084,403.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.62 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $0.0001 per share
(b)	Name of Issuer: Seanergy Maritime Holdings Corp.
(c)	Address of Issuer's Principal Executive Offices: 154 Vouliagmenis Avenue, Glyfada, GREECE , 166 74.
Item 1 Comment: Explanatory Note: This Amendment No. 3 (this "Amendment No. 3") amends and supplements the Schedule 13D filed with the U.S. Securities and Exchange Commission (the "Commission") on March 31, 2023, as amended and supplemented by Amendment No. 1 to Schedule 13D filed with the Commission on December 28, 2023 and Amendment No. 2 to Schedule 13D filed with the Commission on February 28, 2025 ("Amendment No. 2", and as further amended and supplemented by this Amendment No. 3, the "Schedule 13D") by Stamatios Tsantanis (the "Reporting Person") to reflect an increase in the beneficial ownership by the Reporting Person of shares of common stock (the "Common Stock") of Seanergy Maritime Holdings Corp., a Marshall Islands corporation (the "Issuer"). Capitalized terms used herein but not otherwise defined shall have the meaning set forth in Amendment No. 2. Unless indicated otherwise, all items left blank remain unchanged, and any items which are amended below are deemed to amend and update the existing items in Amendment No. 2.
Item 2.	Identity and Background
(d)	The Reporting Person has not been convicted in a criminal proceeding during the last five years.
(e)	During the last five years, the Reporting Person has not been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws. Except as set forth in this Amendment No. 3, there are no material changes to this Item 2 from Amendment No. 2.
Item 3.	Source and Amount of Funds or Other Consideration
	The information set forth in Item 6 is incorporated herein by reference. Except as set forth in this Amendment No. 3, there are no material changes to this Item 3 from Amendment No. 2.
Item 5.	Interest in Securities of the Issuer
(a)	Aggregate number and percentage of class beneficially owned: 2,084,403 shares, or approximately 9.62% of the class, based on 21,668,198 shares of Common Stock outstanding as of March 27, 2026, based on information received from the Issuer.
(b)	The Reporting Person has sole voting and investment power with respect to the Common Stock.
(c)	On July 18, 2025, 50 call options held by the Reporting Person to purchase 5,000 shares of Common Stock with an average exercise price of $8.00 expired unexercised. On October 17, 2025, the Reporting Person exercised 50 call options to purchase 5,000 shares of Common Stock with an exercise price of $8.00 per share. On October 23, 2025, the Reporting Person sold 1,000 shares of Common Stock at an average price of $8.22 per share. The information set forth in Item 3 is incorporated herein by reference. Except as described herein, no transactions in the Common Stock have been effected by the Reporting Person during the past 60 days.
(d)	No other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, any of the shares of Common Stock beneficially owned by the Reporting Persons.
(e)	Not applicable.
Item 6.	Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer
	As described herein, the Reporting Person, in his capacity as an executive officer of the Issuer, has been, and is expected in the future to be, granted shares of Common Stock in accordance with the Issuer's 2011 Equity Incentive Plan, as amended. On March 12, 2025, 196,000 shares of Common Stock were issued and on March 6, 2026, 198,000 shares of Common Stock were issued. These shares of Common Stock are subject to vesting provisions, as follows: 78,400 shares of Common Stock will vest on September 14, 2026, 39,600 shares of Common Stock will vest on September 7, 2026, 59,400 shares of Common Stock will vest on March 8, 2027 and 79,200 shares of Common Stock will vest on September 8, 2027. Except as set forth in this Amendment No. 3, there are no material changes to this Item 6 from Amendment No. 2.

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.

Tsantanis Stamatios

Signature:	/s/ Stamatios Tsantanis
Name/Title:	Stamatios Tsantanis
Date:	03/31/2026

FAQ

How many Seanergy Maritime (SHIP) shares does Stamatios Tsantanis currently beneficially own?

Stamatios Tsantanis beneficially owns 2,084,403 Seanergy Maritime shares. This represents about 9.62% of the company’s common stock, based on 21,668,198 shares outstanding as of March 27, 2026, and he holds sole voting and investment power over these shares.

What percentage of Seanergy Maritime (SHIP) is owned by Stamatios Tsantanis according to this Schedule 13D/A?

Tsantanis reports ownership of approximately 9.62% of Seanergy Maritime’s common stock. The percentage is calculated using 21,668,198 shares outstanding as of March 27, 2026, as reported by the issuer, and reflects his total beneficial holdings.

What recent option and share transactions did Stamatios Tsantanis report for Seanergy Maritime (SHIP)?

Tsantanis reported both option expirations and share transactions. On July 18, 2025, call options on 5,000 shares at $8.00 expired unexercised. On October 17, 2025, he exercised call options for 5,000 shares at $8.00, then sold 1,000 shares on October 23, 2025 at $8.22.

What equity awards did Stamatios Tsantanis receive under Seanergy Maritime’s 2011 Equity Incentive Plan?

Tsantanis received two notable equity awards under the 2011 plan. He was issued 196,000 shares of common stock on March 12, 2025 and 198,000 shares on March 6, 2026, each subject to vesting schedules extending through September 2027.

When will the recently granted Seanergy Maritime (SHIP) shares to Tsantanis vest?

The granted shares vest in several tranches through 2027. Vesting dates cover 78,400 shares on September 14, 2026, 39,600 shares on September 7, 2026, 59,400 shares on March 8, 2027, and 79,200 shares on September 8, 2027.

Does any other person share voting or dispositive power over Seanergy Maritime shares held by Stamatios Tsantanis?

No other person shares voting or dispositive power over these shares. The filing states that Tsantanis has sole voting and investment power regarding his 2,084,403 beneficially owned Seanergy Maritime common shares, with no shared authority disclosed.