[Form 4] Castellum, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Castellum, Inc. (CTM) reported a director equity grant. On 11/11/2025, director C. Thomas McMillen was granted 100,000 stock options with an exercise price of $1.19 per share under the Second Amended 2021 Stock Incentive Plan.

The options relate to 100,000 shares of common stock, vesting ratably over twenty months commencing December 1, 2025, and expiring on 11/10/2032. Following the grant, 100,000 derivative securities were beneficially owned, held directly. The filing classifies the transaction as an acquisition of derivative securities as compensation for board service.

Insights

Governance & Equity Compensation Analyst

Routine director option grant; neutral governance event.

Castellum granted 100,000 options at an exercise price of $1.19 to director C. Thomas McMillen on 11/11/2025. The award vests ratably over twenty months starting December 1, 2025 and expires on 11/10/2032. This aligns with standard board compensation structures.

The disclosure indicates 100,000 derivative securities beneficially owned following the transaction, held directly. As a routine equity grant for service, this is administratively neutral for valuation; any impact depends on future vesting and market price at potential exercise.

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).

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^*

McMillen Charles Thomas

(Last) (First) (Middle)

1103 SOUTH CAROLINA AVENUE

(Street)

WASHINGTON DC 20003

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Castellum, Inc. [ CTM ]

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

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

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

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

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
Stock Options	$1.19	11/11/2025		A		100,000		(1)	11/10/2032	Common Stock	100,000	$0	100,000	D

Explanation of Responses:

1. As compensation for his service as an independent member of the Board of Directors, Mr. McMillen received 100,000 stock options granted pursuant to the terms of the Castellum, Inc. Second Amended 2021 Stock Incentive Plan to purchase 100,000 shares of common stock which vest ratably over a period of twenty months commencing December 1, 2025.

Remarks:

	/s/ C. Thomas McMillen	11/13/2025
	** 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 Castellum (CTM) disclose in this Form 4?

A director, C. Thomas McMillen, received 100,000 stock options on 11/11/2025 at an exercise price of $1.19.

What is the vesting schedule for the CTM director’s options?

They vest ratably over twenty months, commencing December 1, 2025.

What is the expiration date of the options reported by CTM?

The options expire on 11/10/2032.

How many shares underlie the options granted by Castellum (CTM)?

The options are exercisable for 100,000 shares of common stock.

How many derivative securities were owned after the transaction?

100,000 derivative securities were beneficially owned following the grant, held directly.

Under what plan were the CTM options granted?

The grant was made under the Second Amended 2021 Stock Incentive Plan.