[Form 4] IRON MOUNTAIN INC Insider Trading Activity

Rhea-AI Filing Summary

IRON MOUNTAIN INC executive Mark Kidd, EVP and GM of Data Centers & ALM, sold 6,000 shares of common stock in an open-market transaction. The shares were sold at an average price of $127.91 per share. After this sale, he directly holds 119,507 shares of IRON MOUNTAIN common stock. The transaction was carried out under a pre-arranged Rule 10b5-1 trading plan adopted on March 20, 2025, indicating it was scheduled in advance rather than timed discretionarily.

Insider Trade Summary 10b5-1

Net Seller: 6,000 shares ($767,460)

Net Sell 1 txn

Insider Kidd Mark

Role EVP, GM Data Centers & ALM

Sold 6,000 shs ($767K)

Type	Security	Shares	Price	Value
Sale	Common Stock, par value $.01 per share	6,000	$127.91	$767K

Holdings After Transaction: Common Stock, par value $.01 per share — 119,507 shares (Direct, null)

Footnotes (1)

1. [object Object]

Key Figures

Shares sold: 6,000 shares Sale price: $127.91 per share Shares held after sale: 119,507 shares +3 more

6 metrics

Shares sold 6,000 shares Open-market sale on May 8, 2026

Sale price $127.91 per share Average transaction price

Shares held after sale 119,507 shares Direct ownership following transaction

Net shares sold 6,000 shares Net-sell direction in transaction summary

Officer title EVP, GM Data Centers & ALM Reporting person’s role at IRON MOUNTAIN

10b5-1 plan adoption date March 20, 2025 Date trading plan was adopted

Key Terms

Rule 10b5-1 trading plan, open-market sale, Common Stock, par value $.01 per share

3 terms

Rule 10b5-1 trading plan regulatory

"The transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 20, 2025."

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

open-market sale financial

"transaction_action": "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

Common Stock, par value $.01 per share financial

"security_title": "Common Stock, par value $.01 per share""

Form 4 Insider Transactions: What Each Field Means →

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).

X

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^*

Kidd Mark

(Last) (First) (Middle)

C/O IRON MOUNTAIN INCORPORATED

85 NEW HAMPSHIRE AVENUE, SUITE 150

(Street)

PORTSMOUTH NEW HAMPSHIRE 03801

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
IRON MOUNTAIN INC [ IRM ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, GM Data Centers & ALM

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/08/2026

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, par value $.01 per share	05/08/2026		S(1)		6,000	D	$127.91	119,507	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. The transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 20, 2025.

Remarks:

	/s/ Christine Zhang, under Power of Attorney dated June 19, 2025, from Mark Kidd	05/11/2026
	** 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)