Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionStandard Life Aberdeen plc
Latest Disclosed Ownership371,208 shares
Latest Disclosed Value $ 37,915,186
Standard Life Aberdeen plc reports 1.73% increase in ownership of IRM1 / Iron Mountain Incorporated

On April 29, 2026 - Standard Life Aberdeen plc filed a 13F-HR form disclosing ownership of 371,208 shares of Iron Mountain Incorporated (MX:IRM1) valued at $37,915,186 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 16, 2026 disclosing 364,889 shares of Iron Mountain Incorporated. This represents a change in shares of 1.73% 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)
2026-04-29 2026-03-31 13F IRON MTN INC DEL COM 46284V101 371,208 6,319 1.73 37,915 25.27 0.0332
2026-01-16 2025-12-31 13F IRON MTN INC DEL COM 46284V101 364,889 -17,745 -4.64 30,268 -21.17 0.0469
2025-11-07 2025-09-30 13F IRON MTN INC DEL COM 46284V101 382,634 42,971 12.65 38,397 10.21 0.0607
2025-07-24 2025-06-30 13F IRON MTN INC DEL COM 46284V101 339,663 31,017 10.05 34,839 31.96 0.0593
2025-05-13 2025-03-31 13F IRON MTN INC DEL COM 46284V101 308,646 -321,390 -51.01 26,402 -59.62 0.0515
2025-01-24 2024-12-31 13F IRON MTN INC DEL COM 46284V101 630,036 3,756 0.60 65,388 -11.36 0.1228
2024-10-25 2024-09-30 13F IRON MTN INC DEL COM 46284V101 626,280 293,425 88.15 73,770 147.30 0.1353
2024-08-09 2024-06-30 13F IRON MTN INC DEL COM 46284V101 332,855 99,515 42.65 29,830 59.38 0.0572
2024-05-09 2024-03-31 13F IRON MTN INC DEL COM 46284V101 233,340 5,456 2.39 18,716 17.36 0.0367
2024-01-31 2023-12-31 13F IRON MTN INC DEL COM 46284V101 227,884 58,480 34.52 15,947 58.35 0.0346
2023-11-07 2023-09-30 13F IRON MTN INC DEL COM 46284V101 169,404 4,058 2.45 10,071 7.21 0.0257
2024-06-20 2023-06-30 13F/A-1 IRON MTN INC DEL COM 46284V101 165,346 8,885 5.68 9,395 13.48 0.0219
2023-08-04 2023-06-30 13F IRON MTN INC DEL COM 46284V101 165,346 8,885 9,395 0.0219
2024-06-20 2023-03-31 13F/A-1 IRON MTN INC DEL COM 46284V101 156,461 9,222 6.26 8,278 12.79 0.0207
2023-04-28 2023-03-31 13F IRON MTN INC DEL COM 46284V101 156,461 9,222 8,278 0.0207
2024-06-20 2022-12-31 13F/A-1 IRON MTN INC DEL COM 46284V101 147,239 10,258 7.49 7,340 21.83 0.0200
2023-02-10 2022-12-31 13F IRON MTN INC DEL COM 46284V101 147,239 10,258 7,340 0.0200
2022-11-10 2022-09-30 13F IRON MTN INC DEL COM 46284V101 136,981 37,498 37.69 6,024 23.24 0.0179
2022-08-05 2022-06-30 13F IRON MTN INC COM 46284V101 99,483 6,021 6.44 4,888 -6.23 0.0154
2022-05-04 2022-03-31 13F IRON MTN INC COM 46284V101 93,462 -67,479 -41.93 5,213 -38.10 0.0133
2022-02-10 2021-12-31 13F/A-1 IRON MTN INC COM 46284V101 160,941 -11,988 -6.93 8,421 10.32 0.0185
2022-02-08 2021-12-31 13F IRON MTN INC COM 46284V101 160,941 -11,988 8,421 0.0061
2021-11-15 2021-09-30 13F IRON MTN INC COM 46284V101 172,929 -1,147 -0.66 7,633 3.60 0.0172
2021-08-10 2021-06-30 13F IRON MTN INC COM 46284V101 174,076 -7,712 -4.24 7,368 9.45 0.0161
2021-05-06 2021-03-31 13F IRON MTN INC COM 46284V101 181,788 12,262 7.23 6,732 34.67 0.0153
2021-02-10 2020-12-31 13F IRON MTN INC COM 46284V101 169,526 6,984 4.30 4,999 14.79 0.0122
2020-10-21 2020-09-30 13F IRON MTN INC COM 46284V101 162,542 -12,909 -7.36 4,355 -4.89 0.0116
2020-08-10 2020-06-30 13F IRON MTN INC COM 46284V101 175,451 -4,148 -2.31 4,579 7.11 0.0124
2020-05-13 2020-03-31 13F IRON MTN INC COM 46284V101 179,599 -292,895 -61.99 4,275 -71.61 0.0136
2020-02-18 2019-12-31 13F IRON MTN INC COM 46284V101 472,494 -4,324 -0.91 15,059 -2.51 0.0364
2019-11-13 2019-09-30 13F IRON MTN INC COM 46284V101 476,818 -3,840 -0.80 15,447 2.67 0.0385
2019-08-13 2019-06-30 13F IRON MTN INC COM 46284V101 480,658 -2,292 -0.47 15,045 -12.15 0.0334
2019-05-14 2019-03-31 13F IRON MTN INC COM 46284V101 482,950 31,849 7.06 17,125 18.05 0.0371
2019-02-12 2018-12-31 13F IRON MTN INC COM 46284V101 451,101 3,985 0.89 14,506 -6.03 0.0344
2018-11-20 2018-09-30 13F/A-1 IRON MTN INC COM 46284V101 447,116 7,961 1.81 15,437 0.33 0.0288
2018-11-13 2018-09-30 13F IRON MTN INC COM 46284V101 447,116 7,961 15,437
2018-08-09 2018-06-30 13F IRON MTN INC COM 46284V101 439,155 19,055 4.54 15,386 11.44 0.0296
2018-05-15 2018-03-31 13F IRON MTN INC COM 46284V101 420,100 20,787 5.21 13,807 -8.37 0.0274
2018-02-12 2017-12-31 13F IRON MTN INC COM 46284V101 399,313 109,069 37.58 15,068 33.45 0.0288
2017-11-14 2017-09-30 13F IRON MTN INC COM 46284V101 290,244 290,244 11,291 0.0206
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.