IRON MOUNTAIN INC

PublicCIK: 1020569
IRMNYSE
Location

PORTSMOUTH, NH

13F Filings

Institutional Holders

IRON MOUNTAIN INCIRM— Latest position per institution from SEC 13F filings

15

Institutional holders

294.74M

Total shares held

25.51B

Estimated value

14.74M

Avg. position size

1

CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM

CIK 1081019

Shares

54.89M

Value

434.53K

Filed

Jun 30, 2026

2

VANGUARD GROUP INC

CIK 102909

Shares

46.63M

Value

3.87B

Filed

Dec 31, 2025

3

BLACKROCK, INC.

CIK 2012383

Shares

33.57M

Value

4.24B

Filed

Jun 30, 2026

4

BLACKROCK FINANCE, INC.

CIK 1364742

Shares

27.89M

Value

2.50B

Filed

Jun 30, 2024

5

VANGUARD PORTFOLIO MANAGEMENT LLC

CIK 2100121

Shares

25.57M

Value

3.23B

Filed

Jun 30, 2026

6

VANGUARD CAPITAL MANAGEMENT LLC

CIK 2100119

Shares

18.95M

Value

2.39B

Filed

Jun 30, 2026

7

STATE STREET CORP

CIK 93751

Shares

17.63M

Value

2.24B

Filed

Jun 30, 2026

8

COHEN & STEERS, INC.

CIK 1284812

Shares

12.02M

Value

1.52M

Filed

Jun 30, 2026

9

GEODE CAPITAL MANAGEMENT, LLC

CIK 1214717

Shares

8.65M

Value

1.09B

Filed

Jun 30, 2026

10

FMR LLC

CIK 315066

Shares

7.87M

Value

994.36M

Filed

Jun 30, 2026

11

DIMENSIONAL FUND ADVISORS LP

CIK 354204

Shares

4.63M

Value

584.31M

Filed

Jun 30, 2026

12

MORGAN STANLEY

CIK 895421

Shares

4.43M

Value

559.16M

Filed

Jun 30, 2026

13

PRINCIPAL FINANCIAL GROUP INC

CIK 1126328

Shares

4.37M

Value

552.40M

Filed

Jun 30, 2026

14

CHARLES SCHWAB INVESTMENT MANAGEMENT INC

CIK 884546

Shares

4.26M

Value

538.52M

Filed

Jun 30, 2026

15

SIXTH STREET PARTNERS MANAGEMENT COMPANY, L.P.

CIK 1812095

Shares

4.26M

Value

538.52M

Filed

Jun 30, 2026

16

NORTHERN TRUST CORP

CIK 73124

Shares

4.22M

Value

533.40M

Filed

Jun 30, 2026

17

NORGES BANK

CIK 1374170

Shares

4.21M

Value

532.36M

Filed

Jun 30, 2026

18

INVESCO LTD.

CIK 914208

Shares

4.07M

Value

513.53M

Filed

Jun 30, 2026

19

PICTET ASSET MANAGEMENT SA

CIK 1361570

Shares

3.37M

Value

191.47M

Filed

Jun 30, 2023

20

LEGAL & GENERAL GROUP PLC

CIK 764068

Shares

3.24M

Value

409.84M

Filed

Jun 30, 2026

Data sourced from SEC Form 13F institutional holdings reports. Positions reflect the most recent filing per institution.