Martin Marietta COO reports 13,661 share holding

Martin Marietta Materials EVP and COO Christopher William Samborski filed an initial ownership report showing 13,661 shares of Common Stock held directly as of May 1, 2026.

Rhea-AI Filing Summary

Martin Marietta Materials EVP and COO Christopher William Samborski filed an initial ownership report showing 13,661 shares of Common Stock held directly as of May 1, 2026. This Form 3 filing establishes his baseline equity stake as a company officer, without reporting any recent buy or sell transactions.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Samborski Christopher William

Role EVP, COO

Type	Security	Shares	Price	Value
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 13,661 shares (Direct)

Key Figures

Common Stock held: 13,661 shares

1 metrics

Common Stock held 13,661 shares Direct ownership following reported position as of May 1, 2026

Key Terms

Common Stock, direct ownership, Form 3

3 terms

Common Stock financial

"security_title: "Common Stock""

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

direct ownership financial

"ownership_type: "direct" and ownership_code: "D""

Form 3 regulatory

"INSIDER FILING DATA (Form 3)"

Form 3 is the initial public filing that officers, directors and large shareholders must submit to report their ownership of a company’s securities when they become insiders. It acts like an opening inventory sheet that gives investors a starting point to see who holds significant stakes and to spot later trades or potential conflicts of interest, helping assess insider confidence and transparency.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does the Martin Marietta (MLM) Form 3 filing show for Christopher Samborski?

The filing shows EVP and COO Christopher William Samborski directly holds 13,661 shares of Martin Marietta Common Stock as of May 1, 2026. This Form 3 serves as his initial insider ownership statement, not a record of a new transaction.

Is the Martin Marietta (MLM) Form 3 a buy or sell by the COO?

The Form 3 for Martin Marietta’s COO does not record a buy or sell. It simply reports an existing direct holding of 13,661 Common Stock shares as of May 1, 2026, establishing his baseline ownership position as an officer.

How many Martin Marietta (MLM) shares does EVP and COO Samborski own?

EVP and COO Christopher William Samborski is reported to directly own 13,661 shares of Martin Marietta Common Stock following the reported position as of May 1, 2026. The filing does not indicate any derivative securities or indirect ownership interests.

Does the Martin Marietta (MLM) Form 3 show any option exercises or derivatives?

The Form 3 excerpt for Martin Marietta’s COO shows no derivative securities listed. It reports only a direct holding of 13,661 Common Stock shares as of May 1, 2026, with no options, warrants, or other derivative positions disclosed in this data.

What type of ownership does the Martin Marietta (MLM) COO report in the Form 3?

Christopher William Samborski reports direct ownership of Martin Marietta shares, coded as “D” for direct. The position consists of 13,661 Common Stock shares as of May 1, 2026, with no indirect holdings shown in the provided information.

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

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Accepted by SEC EDGAR 05/05/2026 - 04:18 PM EDT Learn about SEC filing dates

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^*

Samborski Christopher William

(Last) (First) (Middle)

4123 PARKLAKE AVE

(Street)

RALEIGH NORTH CAROLINA 27612

(City) (State) (Zip)

UNITED STATES

(Country)

2. Date of Event Requiring Statement (Month/Day/Year)
05/01/2026

3. Issuer Name and Ticker or Trading Symbol
MARTIN MARIETTA MATERIALS INC [ MLM ]

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)

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

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 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	13,661	D

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

Explanation of Responses:

Remarks:

Exhibit 24.1 - Power of Attorney

	/s/ Sara W. Brown, attorney-in-fact	05/05/2026
	** 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)