Castellum GC buys 1,202 shares via ESPP

Castellum, Inc. General Counsel and Secretary Tammy L. Martin made an open-market purchase of company stock under the 2025 Employee Stock Purchase Plan.

Rhea-AI Filing Summary

Castellum, Inc. General Counsel and Secretary Tammy L. Martin made an open-market purchase of company stock under the 2025 Employee Stock Purchase Plan. She bought 1,202 shares of common stock at a price of $0.612 per share, bringing her direct holdings to 15,031 shares. The plan purchase price reflected a 15% discount to the closing price of Castellum’s common stock on June 30, 2026.

Insider Trade Summary

Net Buyer: 1,202 shares

Net Buy 1 txn

Insider MARTIN TAMMY L

Role General Counsel and Secretary

Bought 1,202 shs ($735.62)

Type	Security	Shares	Price	Value
Purchase	Common Stock	1,202	$0.612	$735.62

Holdings After Transaction: Common Stock — 15,031 shares (Direct)

Footnotes (1)

1. F1. Pursuant to the terms of the Castellum, Inc. 2025 Employee Stock Purchase Plan, the reporting person purchased 1,202 shares of common stock of the Registrant. The per share purchase price was calculated at a discount of fifteen percent to the closing price of the Registrant's common stock as quoted on the NYSE American LLC on June 30, 2026.

Key Figures

Shares purchased: 1,202 shares Purchase price: $0.612 per share Holdings after transaction: 15,031 shares +1 more

4 metrics

Shares purchased 1,202 shares Common stock bought under 2025 Employee Stock Purchase Plan

Purchase price $0.612 per share Open-market purchase on July 1, 2026

Holdings after transaction 15,031 shares Direct ownership after ESPP purchase

ESPP discount 15% Discount to June 30, 2026 closing price

Key Terms

Employee Stock Purchase Plan, open-market purchase, common stock, closing price

4 terms

Employee Stock Purchase Plan financial

"Pursuant to the terms of the Castellum, Inc. 2025 Employee Stock Purchase Plan, the reporting person purchased 1,202 shares"

An employee stock purchase plan is a company program that lets workers buy shares through small payroll deductions, often at a discount to the market price and after a set offering period. Think of it like a workplace savings plan that turns into ownership: it encourages employees to share in the company’s success and can create predictable buying or selling of stock that investors watch because it affects supply, demand and employee incentives.

open-market purchase financial

"transaction_action: "open-market purchase" for 1,202 shares of Common Stock"

An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.

common stock financial

"purchased 1,202 shares of common stock of the Registrant"

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.

closing price financial

"discount of fifteen percent to the closing price of the Registrant's common stock"

FAQ

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

What insider transaction did Castellum (CTM) report for Tammy L. Martin?

Castellum reported that General Counsel and Secretary Tammy L. Martin bought 1,202 shares of common stock. The purchase was made through the 2025 Employee Stock Purchase Plan at a discounted price, increasing her direct ownership stake in the company.

How many Castellum (CTM) shares does Tammy L. Martin hold after this transaction?

After the reported transaction, Tammy L. Martin directly holds 15,031 shares of Castellum common stock. This figure reflects her position following the 1,202-share purchase completed through the company’s 2025 Employee Stock Purchase Plan.

At what price did Tammy L. Martin purchase Castellum (CTM) shares?

Tammy L. Martin purchased Castellum common stock at $0.612 per share. This per-share price was calculated with a 15% discount to the closing price of Castellum’s stock quoted on the NYSE American on June 30, 2026.

Was the Castellum (CTM) insider purchase made under an employee stock plan?

Yes. The purchase of 1,202 Castellum shares by Tammy L. Martin was made under Castellum’s 2025 Employee Stock Purchase Plan, which allows eligible employees to buy company stock at a discount to the market closing price.

Is the July 2026 Castellum (CTM) insider transaction a buy or sell?

The July 2026 insider transaction is a buy. General Counsel and Secretary Tammy L. Martin acquired 1,202 shares of Castellum common stock, classified as an open-market purchase under the 2025 Employee Stock Purchase Plan.

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

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Accepted by SEC EDGAR 07/02/2026 - 04:05 PM EDT Learn about SEC filing dates

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^*

MARTIN TAMMY L

(Last) (First) (Middle)

1934 OLD GALLOWS ROAD, SUITE 350

(Street)

VIENNA VIRGINIA 22182

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	General Counsel and Secretary

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
07/01/2026

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

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

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

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	07/01/2026		P		1,202	A	$0.612(1)	15,031	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. Pursuant to the terms of the Castellum, Inc. 2025 Employee Stock Purchase Plan, the reporting person purchased 1,202 shares of common stock of the Registrant. The per share purchase price was calculated at a discount of fifteen percent to the closing price of the Registrant's common stock as quoted on the NYSE American LLC on June 30, 2026.

Remarks:

	/s/ Tammy L. Martin	07/02/2026
	** 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 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.
* Form 4: SEC 1474 (03-26)