STOCK TITAN

Amentum (AMTM) CTO vests 9,072 RSUs with 2,731 shares withheld

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Amentum Holdings, Inc. Chief Technology Officer Jill L. Bruning reported routine equity compensation activity. On May 6, 2026, restricted stock units vested and were settled into 9,072 shares of common stock, reflecting an exercise of derivative securities.

To cover tax obligations on the vesting, Bruning tendered 2,731 shares of common stock at $24.89 per share as a tax-withholding disposition, rather than selling shares in the open market. After these transactions, she directly holds 200,188 shares of common stock and 9,073 restricted stock units. Footnotes note that each restricted stock unit represents a right to receive one share and that the units vest in two equal installments at the 18‑month and three‑year anniversaries of the grant date.

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Insider Bruning Jill L
Role Chief Technology Officer
Type Security Shares Price Value
Exercise Restricted Stock Units 9,072 $0.00 --
Exercise Common Stock 9,072 $0.00 --
Tax Withholding Common Stock 2,731 $24.89 $68K
Holdings After Transaction: Restricted Stock Units — 9,073 shares (Direct, null); Common Stock — 200,188 shares (Direct, null)
Footnotes (1)
  1. Represents distribution of AMTM common stock upon vesting of restricted stock units. Includes 117 shares acquired under the employee stock purchase plan in March 2026. Represents number of shares of AMTM common stock tendered for tax withholding upon vesting of restricted stock units. Each restricted stock unit represents a contingent right to receive one share of AMTM common stock. One-half of the restricted stock units shall vest and be delivered on the 18th month and three-year anniversaries of the date of grant.
RSUs vested and exercised 9,072 shares Restricted stock units converted to Amentum common stock on May 6, 2026
Shares withheld for taxes 2,731 shares at $24.89 Common stock tendered for tax withholding on RSU vesting
Direct common shares after transaction 200,188 shares Total Amentum common stock directly held post‑transaction
Outstanding restricted stock units 9,073 RSUs RSU balance following reported vesting and delivery
ESPP shares included in holdings 117 shares Shares acquired under employee stock purchase plan in March 2026
Restricted Stock Units financial
"Represents distribution of AMTM common stock upon vesting of restricted stock units."
Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.
employee stock purchase plan financial
"Includes 117 shares acquired under the employee stock purchase plan in March 2026."
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.
tax withholding financial
"Represents number of shares of AMTM common stock tendered for tax withholding upon vesting of restricted stock units."
Tax withholding is the practice of taking a portion of a payment—such as wages, dividends, or sale proceeds—before it reaches the recipient and sending that portion to the tax authority as an advance on the recipient’s eventual tax bill. For investors it matters because withholding reduces immediate cash received and affects after‑tax returns, estimated tax payments, and whether you may owe more or receive a refund when taxes are finally calculated, like having a small automatic savings set aside for your tax bill.
contingent right financial
"Each restricted stock unit represents a contingent right to receive one share of AMTM common stock."
vest and be delivered financial
"One-half of the restricted stock units shall vest and be delivered on the 18th month and three-year anniversaries of the date of grant."
SEC Form 4
FORM 4UNITED 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*
Bruning Jill L

(Last)(First)(Middle)
C/O AMENTUM HOLDINGS, INC.
4800 WESTFIELDS BOULEVARD, SUITE 400

(Street)
CHANTILLY VIRGINIA 20151

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
Amentum Holdings, Inc. [ AMTM ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
Chief Technology Officer
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/06/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm 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)
CodeVAmount(A) or (D)Price
Common Stock05/06/2026M9,072A(1)200,188(2)D
Common Stock05/06/2026F2,731(3)D$24.89197,457D
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Restricted Stock Units(4)05/06/2026M9,072 (5) (5)Common Stock9,072$09,073D
Explanation of Responses:
1. Represents distribution of AMTM common stock upon vesting of restricted stock units.
2. Includes 117 shares acquired under the employee stock purchase plan in March 2026.
3. Represents number of shares of AMTM common stock tendered for tax withholding upon vesting of restricted stock units.
4. Each restricted stock unit represents a contingent right to receive one share of AMTM common stock.
5. One-half of the restricted stock units shall vest and be delivered on the 18th month and three-year anniversaries of the date of grant.
Remarks:
/s/ Indira Lall, Attorney-in-fact05/07/2026
** Signature of Reporting PersonDate
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)

FAQ

What insider transactions did Amentum (AMTM) CTO Jill Bruning report?

Jill Bruning reported RSU vesting that delivered 9,072 Amentum common shares and a related tax-withholding disposition of 2,731 shares. These entries reflect routine compensation events rather than open-market buying or selling of stock.

Did the Amentum (AMTM) CTO buy or sell shares on the open market?

The filing shows no open-market purchases or sales. Shares were acquired through vesting of restricted stock units and some were tendered back solely to satisfy tax withholding obligations tied to that vesting event.

How many Amentum (AMTM) shares does the CTO hold after these transactions?

Following the reported transactions, Jill Bruning directly holds 200,188 shares of Amentum common stock. She also has 9,073 restricted stock units outstanding, each representing a contingent right to receive one additional Amentum common share at future vesting dates.

What do the 9,072 Amentum (AMTM) restricted stock units represent?

The 9,072 restricted stock units that vested represent previously granted equity awards converting into the same number of Amentum common shares. Each unit was a contingent right to one share, with vesting tied to 18‑month and three‑year anniversaries of the original grant.

Why were 2,731 Amentum (AMTM) shares used for tax withholding?

The 2,731 shares were tendered to cover tax obligations arising from the RSU vesting. Instead of paying cash taxes, a portion of the newly delivered Amentum shares was withheld and returned, a standard mechanism that does not involve open-market stock sales.

What additional share acquisitions are noted for Amentum (AMTM) CTO Jill Bruning?

A footnote states her holdings include 117 Amentum shares acquired under the employee stock purchase plan in March 2026. This plan-based accumulation is separate from the RSU vesting and reflects ongoing employee participation in Amentum’s stock purchase program.