Iron Mountain

IRM • NYSE

Iron Mountain is a reit - specialty company in the real estate sector on NYSE, led by William L. Meaney, with a market cap of $27.4B. As of Q3 2025, 84% of shares are held by 987 institutional investors, with VANGUARD GROUP INC as the largest holder at 16.0%.

CEOWilliam L. Meaney

Market Cap$27.4B

REIT - Specialty

Real Estate

Employees27.0K

Websiteironmountain.com

Country

United States of America

Overview

Overview of institutional ownership in IRM as of Q3 2025 with a market cap of $30.1B

All Institutions

Institutions: 987
Value Held: $25.4B
Shares Held: 249.1M
Avg Position: $25.7M
Median Position: $783.9K

Hedge Funds

Hedge Funds: 53
Value Held: $772.0M
Shares Held: 7.6M
Avg Position: $14.6M
Median Position: $1.4M

Ownership Breakdown

Institutional (non-HF)

81.81%

$24.6B

Hedge Funds

2.56%

$772.0M

Retail & Other

15.63%

$4.7B

Based on market cap of $30.1B as of Q3 2025. Institutional (non-HF) excludes hedge funds to avoid double counting.

Biggest Investors

Institutions with the largest positions in IRM as of Q3 2025

Institution	Key People	Position Value	Ownership	Owned Since	Total AUM (Long)
VANGUARD GROUP INC Institution	Salim Ramji CEO	$4.8B 0.07% of portfolio	16.00% 47.3M shares	≤ Q2 2013 Held for 12y 6m+	$6.69T
BlackRock, Inc. Institution	Laurence D. Fink CEO	$3.2B 0.06% of portfolio	10.74% 31.7M shares	≤ Q2 2013 Held for 12y 6m+	$5.67T
STATE STREET CORP Institution	Ronald P. O'Hanley CEO	$1.8B 0.06% of portfolio	5.80% 17.1M shares	≤ Q2 2013 Held for 12y 6m+	$2.88T
COHEN & STEERS INC Institution	Joseph M. Harvey CEO	$1.6B 2.94% of portfolio	5.33% 15.7M shares	Q2 2020 Held for 5y 6m	$54.7B
GEODE CAPITAL MANAGEMENT LLC ETF Provider	David Kenneth Lane CEO	$831.7M 0.05% of portfolio	2.77% 8.2M shares	≤ Q2 2013 Held for 12y 6m+	$1.57T
FMR LLC Institution	-	$801.1M 0.04% of portfolio	2.66% 7.9M shares	≤ Q2 2013 Held for 12y 6m+	$1.92T
Invesco Ltd. ETF Provider	Brian Christopher Hartigan CEO	$516.5M 0.08% of portfolio	1.72% 5.1M shares	≤ Q2 2013 Held for 12y 6m+	$633.08B
DIMENSIONAL FUND ADVISORS LP Long Only Manager	David Paul Butler CEO	$443.2M 0.10% of portfolio	1.47% 4.3M shares	≤ Q2 2013 Held for 12y 6m+	$466.34B
NORTHERN TRUST CORP Institution	Michael G. O'Grady CEO	$411.0M 0.05% of portfolio	1.37% 4.0M shares	≤ Q2 2013 Held for 12y 6m+	$782.03B
SCHWAB CHARLES INVESTMENT MANAGEMENT INC Long Only Manager	Omar Aguilar Chavez CEO	$374.6M 0.06% of portfolio	1.24% 3.7M shares	≤ Q2 2013 Held for 12y 6m+	$620.51B

Net Capital Flow

Institutional buying and selling activity for IRM in Q3 2025

Traded: +$527.8M
Buyers: 427
Sellers: 474
Total Bought: +$1.6B
Total Sold: −$1.1B
Avg Position: $23.6M

Biggest Buyers

Institution	Net Bought	Current Position
UBS GLOBAL ASSET MANAGEMENT AMERICAS INC Long Only Manager	+$276.1M +2.7M shares	$322.3M 3.2M shares
COHEN & STEERS INC Institution	+$201.8M +2.0M shares	$1.6B 15.7M shares
FMR LLC Institution	+$118.3M +1.2M shares	$801.1M 7.9M shares
V Vontobel Holding Ltd. Institution	+$109.9M +1.1M shares	$109.9M 1.1M shares
Contour Asset Management LLC Hedge Fund•Long/Short	+$84.7M +830.5K shares	$322.7M 3.2M shares
Invesco Ltd. ETF Provider	+$79.2M +776.9K shares	$516.5M 5.1M shares
CENTERSQUARE INVESTMENT MANAGEMENT LLC Real Assets	+$49.3M +483.5K shares	$256.3M 2.5M shares
BlackRock, Inc. Institution	+$43.9M +430.4K shares	$3.2B 31.7M shares
AQR CAPITAL MANAGEMENT LLC Hedge Fund•Multi-Strategy	+$35.6M +351.5K shares	$46.4M 457.5K shares
BAMCO INC /NY/ Long Only Manager	+$33.6M +329.3K shares	$44.5M 436.8K shares

Biggest Sellers

Institution	Net Sold	Current Position
WELLINGTON MANAGEMENT CO LLP Long Only Manager	−$126.9M −1.2M shares	$25.4M 248.9K shares
$DEUTSCHE BANK AG\ logo$ DEUTSCHE BANK AG\ Institution	−$54.9M −539.0K shares	$294.7M 2.9M shares
A Amundi Institution	−$54.8M −515.5K shares	$115.4M 1.1M shares
GOLDMAN SACHS GROUP INC Institution	−$53.6M −525.9K shares	$138.0M 1.4M shares
Z Zurich Insurance Group Ltd/FI Institution	−$52.7M −513.8K shares	Sold Off 0 shares
D D. E. Shaw & Co., Inc. Institution	−$44.8M −439.9K shares	$14.7M 144.0K shares
VOLORIDGE INVESTMENT MANAGEMENT, LLC Hedge Fund•Multi-Strategy	−$39.2M −382.1K shares	Sold Off 0 shares
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	−$37.2M −364.9K shares	$10.0M 98.2K shares
UBS Group AG Institution	−$37.1M −363.9K shares	$146.4M 1.4M shares
AEW CAPITAL MANAGEMENT L P Real Assets	−$31.0M −304.4K shares	$32.1M 315.3K shares

Entry and Exit Activity

Institutions that initiated new positions or completely exited IRM in Q3 2025

New Positions: 36
New Value: $12.6M
Exited Positions: 89
Exited Value: $240.2M

New Positions

Institution	Position Value
INTACT INVESTMENT MANAGEMENT INC. Private Equity	$3.6M 35.2K shares
F Fieldview Capital Management, LLC Hedge Fund•Long/Short	$3.1M 30.3K shares
T TEMA ETFS LLC Institution	$2.3M 22.4K shares
LDR Capital Management LLC Hedge Fund•Sector	$1.1M 11.1K shares
JACKSON SQUARE CAPITAL, LLC RIA/Wealth	$611.5K 6.0K shares
A Alliance Wealth Advisors, LLC /UT RIA/Wealth	$417.5K 4.1K shares
F FLOW TRADERS U.S. LLC Institution	$298.8K 2.9K shares
C Camden Capital, LLC RIA/Wealth	$267.0K 2.6K shares
S SPIREPOINT PRIVATE CLIENT, LLC RIA/Wealth	$243.3K 2.4K shares
HOEY INVESTMENTS, INC RIA/Wealth	$125.9K 1.2K shares

Exited Positions

Institution	Previous Position
Z Zurich Insurance Group Ltd/FI Institution	$52.7M 513.8K shares
VOLORIDGE INVESTMENT MANAGEMENT, LLC Hedge Fund•Multi-Strategy	$39.2M 382.1K shares
J JANE STREET GROUP, LLC Institution	$15.4M 149.9K shares
S SG Americas Securities, LLC Institution	$12.9M 125.3K shares
E Employees Retirement System of Texas Institution	$12.0M 117.3K shares
Weiss Asset Management LP Hedge Fund•Multi-Strategy	$11.1M 108.4K shares
A AXA Institution	$10.4M 101.8K shares
Kingstone Capital Partners Texas, LLC RIA/Wealth	$10.1M 98.4K shares
H HRT FINANCIAL LLC Institution	$8.6M 83.7K shares
E Eisler Capital Management Ltd. Institution	$7.6M 74.0K shares

Options Activity

Institutions with the largest Call and Put options positions in IRM as of Q3 2025

Call Positions: 21
Call Value: $92.8M
Put Positions: 24
Put Value: $100.8M

Call Positions

Institution	Position Value
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$31.5M 3.1K contracts
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$13.8M 1.4K contracts
SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC Hedge Fund•Long/Short	$10.2M 1.0K contracts
CAPITAL FUND MANAGEMENT S.A. Hedge Fund•Quant Macro	$8.3M 815.0 contracts
S Squarepoint Ops LLC Hedge Fund•Quant	$6.2M 605.0 contracts
W WOLVERINE TRADING, LLC Institution	$4.8M 476.0 contracts
J JANE STREET GROUP, LLC Institution	$3.8M 369.0 contracts
MILLENNIUM MANAGEMENT LLC Hedge Fund•Multi-Strategy	$3.6M 353.0 contracts
BANK OF AMERICA CORP /DE/ Institution	$2.8M 270.0 contracts
D D. E. Shaw & Co., Inc. Institution	$2.6M 251.0 contracts

Put Positions

Institution	Position Value
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$18.2M 1.8K contracts
GOLDMAN SACHS GROUP INC Institution	$18.0M 1.8K contracts
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$13.7M 1.3K contracts
CAPITAL FUND MANAGEMENT S.A. Hedge Fund•Quant Macro	$11.0M 1.1K contracts
T Twin Tree Management, LP Hedge Fund•Vol Arbitrage	$10.7M 1.0K contracts
S Squarepoint Ops LLC Hedge Fund•Quant	$5.2M 514.0 contracts
Caption Management, LLC Hedge Fund•Long/Short	$5.1M 500.0 contracts
J JANE STREET GROUP, LLC Institution	$3.7M 362.0 contracts
WOLVERINE ASSET MANAGEMENT LLC Hedge Fund•Multi-Strategy	$2.9M 287.0 contracts
W WOLVERINE TRADING, LLC Institution	$2.8M 275.0 contracts

Most Committed Institutions

Institutions with IRM as the highest % of their portfolio as of Q3 2025

Institution	Key People	Portfolio Weight	Ownership	Owned Since	Total AUM (Long)
Contour Asset Management LLC Hedge Fund•Long/Short	Alpa Shailesh Rana CFO	8.09% $322.7M	1.07% 3.2M shares	Q1 2025 Held for 9 months	$4.0B
W Waterfront Capital Partners, LLC Hedge Fund•Long/Short	Eduardo Abush Managing Partner	7.69% $11.8M	0.04% 115.3K shares	Q1 2024 Held for 1y 9m	$152.8M
FORESIGHT CAPITAL MANAGEMENT ADVISORS, INC. RIA/Wealth	Laurie Sue Stegenga President	4.73% $8.4M	0.03% 82.1K shares	Q4 2023 Held for 2 years	$176.8M
Vert Asset Management LLC Institution	Samuel Chase Adams Managing Partner	4.61% $13.7M	0.05% 134.6K shares	Q4 2021 Held for 4 years	$297.4M
B B&I Capital AG Institution	-	3.63% $10.5M	0.03% 103.0K shares	Q1 2025 Held for 9 months	$288.9M
Marble Harbor Investment Counsel, LLC RIA/Wealth	Paul Robert Davis CIO	3.48% $33.2M	0.11% 325.3K shares	≤ Q2 2013 Held for 12y 6m+	$954.0M
H HEITMAN REAL ESTATE SECURITIES LLC Real Assets	Jeffrey Donald Yurk Managing Partner	3.30% $48.4M	0.16% 474.4K shares	Q3 2023 Held for 2y 3m	$1.5B
LDR Capital Management LLC Hedge Fund•Sector	Lawrence David Raiman CIO	3.08% $1.1M	0.00% 11.1K shares	Q3 2025 Held for 3 months	$36.7M
A AR ASSET MANAGEMENT INC RIA/Wealth	Annie Anh Ngoc Kim President	2.96% $13.3M	0.04% 130.6K shares	Q1 2020 Held for 5y 9m	$449.4M
COHEN & STEERS INC Institution	Joseph M. Harvey CEO	2.94% $1.6B	5.33% 15.7M shares	Q2 2020 Held for 5y 6m	$54.7B