Castellum Form 4: Director exercises 125,000 options, holdings now 316,015

Rhea-AI Filing Summary

C. Thomas McMillen, a director of Castellum, Inc. (CTM), exercised fully vested stock options on 08/20/2025 and received 125,000 shares of common stock at an exercise price of $0.212 per share. The Form 4 filed 08/21/2025 reports the cash exercise of those options and shows 316,015 shares beneficially owned following the transaction. The options exercised were exercisable immediately and expire 06/30/2031.

Positive

• Director purchased 125,000 shares through exercise of fully vested options, indicating insider acquisition documented in the filing
• Post-transaction beneficial ownership disclosed: 316,015 shares following the exercise
• Options exercisable immediately and disclosed with expiration date (06/30/2031), providing clarity on option terms

Negative

• None.

Insights

Financial Analyst

TL;DR: Director exercised fully vested options for 125,000 shares at $0.212, raising his stake to 316,015 shares.

The filing documents a routine Section 16 stock option exercise: 125,000 options were exercised for common stock at $0.212 per share on 08/20/2025 and reported on Form 4 the following day. The options are fully vested and expire 06/30/2031, and the exercise increased the reporting person\'s beneficial holdings to 316,015 shares. This is a direct acquisition by an insider and is recorded as a standard disclosure under Section 16.

Corporate Governance Expert

TL;DR: Insider reporting shows alignment via equity purchase; transaction is disclosed appropriately on Form 4.

The submission is a properly executed Form 4 indicating the director\'s purchase of common stock through exercising vested options. It includes the transaction date, exercise price, option vesting status, expiration date, and post-transaction beneficial ownership, fulfilling standard disclosure requirements. No additional governance events or amendments are reported in this filing.

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
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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)
08/20/2025

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	08/21/2025		M		125,000	A	$0.212	316,015	D(1)

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	$0.212	08/20/2025		M			125,000	(2)	06/30/2031	Common Stock	125,000	$0.212	0	D

Explanation of Responses:

1. Reflects the issuance of common stock in connection with the cash exercise of stock options.

2. These stock options are fully vested and exercised.

Remarks:

	/s/ C. Thomas McMillen	08/21/2025
	** 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 CTM director C. Thomas McMillen report on Form 4?

The Form 4 reports that C. Thomas McMillen exercised 125,000 stock options on 08/20/2025 and acquired common stock at an exercise price of $0.212 per share.

How many shares does the reporting person beneficially own after the transaction?

The filing shows 316,015 shares beneficially owned following the reported transaction.

Were the options exercised by the director vested and what is their expiration date?

Yes, the filing states the stock options were fully vested and the options expire on 06/30/2031.

When was the transaction executed and when was the Form 4 filed?

The transaction date is 08/20/2025 and the Form 4 was signed and dated 08/21/2025.

What was the exercise price per share for the options exercised?

The exercise price reported for the options was $0.212 per share.