Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionBrookfield Asset Management Inc.
ManagerBruce Flatt
Latest Disclosed Ownership188,255 shares
Latest Disclosed Value $ 19,228,366
Brookfield Asset Management Inc. reports 31.35% increase in ownership of IRM1 / Iron Mountain Incorporated

On May 15, 2026 - Brookfield Asset Management Inc. filed a 13F-HR form disclosing ownership of 188,255 shares of Iron Mountain Incorporated (MX:IRM1) valued at $19,228,366 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 143,320 shares of Iron Mountain Incorporated. This represents a change in shares of 31.35% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F Iron Mountain COM 46284V101 188,255 44,935 31.35 19,228 61.74 0.0148
2026-02-13 2025-12-31 13F Iron Mountain COM 46284V101 143,320 128,205 848.20 11,888 671.95 0.0147
2025-11-14 2025-09-30 13F Iron Mountain COM 46284V101 15,115 922 6.50 1,541 5.84 0.0018
2025-08-15 2025-06-30 13F Iron Mountain COM 46284V101 14,193 171 1.22 1,456 20.65 0.0018
2025-08-14 2025-03-31 13F/A-2 Iron Mountain COM 46284V101 14,022 2,898 26.05 1,206 3.17 0.0016
2025-06-10 2025-03-31 13F/A-1 Iron Mountain COM 46284V101 14,022 2,898 1,206 0.0069
2025-05-15 2025-03-31 13F Iron Mountain COM 46284V101 14,022 2,898 1,206 0.0063
2025-06-10 2024-12-31 13F/A-1 Iron Mountain COM 46284V101 11,124 -6,181 -35.72 1,169 -43.14 0.0071
2025-02-14 2024-12-31 13F Iron Mountain COM 46284V101 11,124 -6,181 1,169 0.0071
2024-11-15 2024-09-30 13F Iron Mountain COM 46284V101 17,305 -148,221 -89.55 2,056 -86.14 0.0116
2024-08-15 2024-06-30 13F Iron Mountain COM 46284V101 165,526 119,952 263.20 14,834 305.85 0.0930
2024-05-15 2024-03-31 13F IRON MOUNTAIN COM 46284V101 45,574 -307,229 -87.08 3,655 -85.20 0.0216
2024-02-14 2023-12-31 13F IRON MTN INC DEL COM 46284V101 352,803 -223,006 -38.73 24,689 -27.88 0.1410
2023-11-14 2023-09-30 13F IRON MTN INC DEL COM 46284V101 575,809 575,809 34,232 0.2140
2023-02-14 2022-12-31 13F IRON MTN INC DEL COM 46284V101 0 -9,512 -100.00 0 -100.00
2022-11-14 2022-09-30 13F IRON MTN INC DEL COM 46284V101 9,512 9,512 418 0.0015
2022-05-16 2022-03-31 13F IRON MTN INC COM 46284V101 0 -25,113 -100.00 0 -100.00
2022-02-14 2021-12-31 13F IRON MTN INC COM 46284V101 25,113 25,113 1,314 0.0051
2016-05-11 2016-03-31 13F IRON MOUNTAIN COM 46284V101 0 0 0 0.0000
2016-02-16 2015-12-31 13F IRON MTN INC COM 46284V101 0 -53,186 -100.00 0 -100.00
2015-12-15 2015-09-30 13F/A-4 IRON MTN INC COM 46284V101 53,186 0 0.00 1,650 0.06 0.0093
2015-11-17 2015-09-30 13F/A-1 IRON MTN INC COM 46284V101 53,186 0 1,650 9,757.0258
2015-11-20 2015-09-30 13F/A-3 IRON MTN INC COM 46284V101 53,186 0 1,650 9,158.5146
2015-11-13 2015-09-30 13F IRON MTN INC COM 46284V101 53,186 1,650
2015-11-17 2015-06-30 13F/A-1 IRON MOUNTAIN COM 46284V101 53,186 14,208 1,649 9,562.5396
2015-12-15 2015-06-30 13F/A-3 IRON MOUNTAIN COM 46284V101 53,186 14,208 36.45 1,649 15.96 0.0097
2015-08-14 2015-06-30 13F IRON MOUNTAIN COM 46284V101 53,186 1,649
2015-05-13 2015-03-31 13F IRON MTN INC COM 46284V101 38,978 -1,498,356 -97.46 1,422 -97.61 0.0076
2015-02-12 2014-12-31 13F IRON MTN COM 46284V101 1,537,334 -1,691,054 -52.38 59,433 -43.62 0.2857
2014-11-12 2014-09-30 13F IRON MTN COM 462846106 3,228,388 -2,312,726 -41.74 105,406 -46.34 0.6216
2014-09-08 2014-06-30 13F/A-1 IRON MTN COM 462846106 5,541,114 388,900 7.55 196,432 38.29 1.2673
2014-08-15 2014-06-30 13F IRON MTN COM 462846106 5,541,114 196,432
2014-05-15 2014-03-31 13F IRON MTN COM 462846106 5,152,214 1,288,200 33.34 142,046 21.10 0.6149
2014-02-14 2013-12-31 13F Iron Mtn COM 462846106 3,864,014 -258,400 -6.27 117,294 5.30 0.6446
2013-11-21 2013-09-30 13F/A-1 Iron Mountain COM 462846106 4,462,214 4,058,695 118,451 611,280.5572
2013-12-10 2013-09-30 13F/A-2 Iron Mountain COM 462846106 4,122,414 3,718,895 921.62 111,387 3.72 0.5746
2013-11-14 2013-09-30 13F Iron Mountain COM 462846106 4,462,214 118,451
2013-12-16 2013-06-30 13F/A-1 IRON MTN COM 462846106 403,519 403,519 107,392 0.5551
2013-08-15 2013-06-30 13F IRON MTN COM 462846106 4,035,190 107,392
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.