[Form 4] Great Lakes Dredge & Dock Corporation Insider Trading Activity

Rhea-AI Filing Summary

Scott Lee Kornblau, SVP & CFO of Great Lakes Dredge & Dock Corp. (GLDD), reported the sale of 59,805 shares of GLDD common stock on 08/11/2025. The filing shows the sale was executed pursuant to a Rule 10b5-1 trading plan adopted May 9, 2025, with a reported weighted average sale price of $11.476 and individual trade prices ranging from $11.36 to $11.68.

After the reported transactions the Form 4 lists 112,130.24 as the amount of securities beneficially owned following the sale. The Form 4 was submitted by one reporting person and signed by an attorney-in-fact acting under power of attorney.

Positive

• Sale executed under a Rule 10b5-1 trading plan, indicating the transaction followed a pre-established procedure
• Weighted average price disclosed ($11.476) and per-trade price range provided ($11.36–$11.68), improving transparency

Negative

• Officer sale of 59,805 shares reduces executive ownership and could be viewed negatively by some investors
• Remaining beneficial ownership figure is reported (112,130.24) but context versus total outstanding shares is not provided in this filing

Insights

Securities Analyst

TL;DR: The CFO sold 59,805 GLDD shares under a pre-established 10b5-1 plan; disclosure provides clear pricing and remaining ownership.

The transaction is a routine, pre-planned insider sale rather than an opportunistic trade, which reduces the likelihood that it was motivated by undisclosed company developments. The filing discloses a weighted average price of $11.476 and a per-trade range of $11.36–$11.68, enabling investors to calculate proceeds. Materiality for investors depends on the size of the sale relative to total insider holdings and free float, information not included in this Form 4.

Corporate Governance Expert

TL;DR: Use of a Rule 10b5-1 plan signals procedural compliance but the insider disposition reduces executive ownership.

The filing confirms the sale was executed under a documented 10b5-1 plan adopted May 9, 2025, which typically provides an affirmative defense to allegations of trading on material nonpublic information. However, the record also shows the officer's beneficial holdings declined by the reported amount to 112,130.24 shares, which may be relevant to governance-minded investors tracking insider alignment with shareholders.

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Kornblau Scott Lee

(Last) (First) (Middle)

C/O GREAT LAKES DREDGE & DOCK CORP.

9811 KATY FREEWAY, SUITE 1200

(Street)

HOUSTON TX 77024

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Great Lakes Dredge & Dock CORP [ GLDD ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
08/11/2025

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

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

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

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/11/2025		S		59,805(1)	D	$11.476(2)	112,130.24	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 9, 2025.

2. Represents the weighted average price. The shares were sold in multiple transactions ranging from $11.36 to $11.68, inclusive. Upon request by the Commission staff, the issuer or security holder of the issuer, the reporting person will provide information regarding the number of shares disposed at each separate price.

	/s/Vivienne R. Schiffer, by Power of Attorney	08/13/2025
	** 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 4 (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.

FAQ

What did GLDD insider Scott Lee Kornblau do on 08/11/2025?

The Form 4 reports a sale of 59,805 shares of Great Lakes Dredge & Dock (GLDD) stock on 08/11/2025.

Was the GLDD sale part of a trading plan?

Yes. The sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 9, 2025.

At what price were the GLDD shares sold?

The Form 4 shows a weighted average sale price of $11.476, with individual transactions ranging from $11.36 to $11.68.

How many GLDD shares does the officer own after the sale?

The filing lists 112,130.24 as the amount of securities beneficially owned following the reported transactions.

Who filed the Form 4 for GLDD insider activity?

The Form 4 was filed by reporting person Kornblau Scott Lee (SVP & CFO) and signed by an attorney-in-fact acting under power of attorney.