Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionUtah Retirement Systems
Latest Disclosed Ownership47,687 shares
Latest Disclosed Value $ 4,870,750
Utah Retirement Systems reports 1.63% decrease in ownership of IRM1 / Iron Mountain Incorporated

On May 15, 2026 - Utah Retirement Systems filed a 13F-HR form disclosing ownership of 47,687 shares of Iron Mountain Incorporated (MX:IRM1) valued at $4,870,750 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 48,479 shares of Iron Mountain Incorporated. This represents a change in shares of -1.63% 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 MTN INC DEL COM 46284V101 47,687 -792 -1.63 4,871 21.11 0.0498
2026-02-17 2025-12-31 13F IRON MTN INC DEL COM 46284V101 48,479 0 0.00 4,021 -18.62 0.0383
2025-11-14 2025-09-30 13F IRON MTN INC DEL COM 46284V101 48,479 430 0.89 4,942 0.26 0.0480
2025-08-14 2025-06-30 13F IRON MTN INC DEL COM 46284V101 48,049 -165 -0.34 4,928 18.80 0.0515
2025-05-15 2025-03-31 13F IRON MTN INC DEL COM 46284V101 48,214 0 0.00 4,148 -18.14 0.0479
2025-02-14 2024-12-31 13F IRON MTN INC DEL COM 46284V101 48,214 100 0.21 5,068 -11.37 0.0558
2024-11-14 2024-09-30 13F IRON MTN INC DEL COM 46284V101 48,114 200 0.42 5,717 33.14 0.0645
2024-08-14 2024-06-30 13F IRON MTN INC DEL COM 46284V101 47,914 -2,200 -4.39 4,294 6.84 0.0510
2024-05-15 2024-03-31 13F IRON MTN INC DEL COM 46284V101 50,114 0 0.00 4,020 14.63 0.0470
2024-02-14 2023-12-31 13F IRON MTN INC DEL COM 46284V101 50,114 300 0.60 3,507 18.41 0.0447
2023-11-14 2023-09-30 13F IRON MTN INC DEL COM 46284V101 49,814 100 0.20 2,961 4.85 0.0423
2023-08-14 2023-06-30 13F IRON MTN INC DEL COM 46284V101 49,714 -1,600 -3.12 2,825 4.01 0.0392
2023-05-16 2023-03-31 13F IRON MTN INC DEL COM 46284V101 51,314 200 0.39 2,715 6.55 0.0393
2023-02-15 2022-12-31 13F IRON MTN INC DEL COM 46284V101 51,114 -500 -0.97 2,548 12.25 0.0404
2022-11-14 2022-09-30 13F IRON MTN INC DEL COM 46284V101 51,614 600 1.18 2,270 -8.62 0.0378
2022-08-16 2022-06-30 13F IRON MTN INC COM 46284V101 51,014 0 0.00 2,484 -12.13 0.0398
2022-05-13 2022-03-31 13F IRON MTN INC COM 46284V101 51,014 -900 -1.73 2,827 4.05 0.0376
2022-02-14 2021-12-31 13F IRON MTN INC COM 46284V101 51,914 100 0.19 2,717 20.70 0.0336
2021-11-16 2021-09-30 13F IRON MTN INC COM 46284V101 51,814 -3,000 -5.47 2,251 -2.97 0.0304
2021-08-16 2021-06-30 13F IRON MTN INC COM 46284V101 54,814 0 0.00 2,320 14.34 0.0299
2021-05-17 2021-03-31 13F IRON MTN INC COM 46284V101 54,814 -2,500 -4.36 2,029 20.13 0.0283
2021-02-16 2020-12-31 13F IRON MTN INC COM 46284V101 57,314 -34,809 -37.79 1,689 -31.56 0.0240
2020-11-16 2020-09-30 13F IRON MTN INC COM 46284V101 92,123 1,500 1.66 2,468 4.31 0.0410
2020-08-13 2020-06-30 13F/A-1 IRON MTN INC COM 46284V101 90,623 -500 -0.55 2,366 9.13 0.0434
2020-08-13 2020-06-30 13F IRON MTN INC COM 46284V101 90,623 -500 2,366 43,425.6725
2020-05-15 2020-03-31 13F IRON MTN INC COM 46284V101 91,123 2,500 2.82 2,168 -23.23 0.0469
2020-02-12 2019-12-31 13F IRON MTN INC COM 46284V101 88,623 500 0.57 2,824 -1.05 0.0496
2019-11-14 2019-09-30 13F IRON MTN INC COM 46284V101 88,123 1,500 1.73 2,854 5.24 0.0543
2019-08-14 2019-06-30 13F IRON MTN INC COM 46284V101 86,623 -618 -0.71 2,712 -12.35 0.0519
2019-05-15 2019-03-31 13F IRON MTN INC COM 46284V101 87,241 -280 -0.32 3,094 9.10 0.0613
2019-02-08 2018-12-31 13F IRON MTN INC COM 46284V101 87,521 900 1.04 2,836 -5.15 0.0641
2018-11-13 2018-09-30 13F IRON MTN INC COM 46284V101 86,621 1,500 1.76 2,990 0.34 0.0579
2018-08-10 2018-06-30 13F IRON MTN INC COM 46284V101 85,121 1,200 1.43 2,980 8.09 0.0617
2018-05-15 2018-03-31 13F IRON MTN INC COM 46284V101 83,921 1,400 1.70 2,757 -11.44 0.0586
2018-02-14 2017-12-31 13F IRON MTN INC COM 46284V101 82,521 4,400 5.63 3,113 2.44 0.0654
2017-11-13 2017-09-30 13F IRON MTN INC COM 46284V101 78,121 500 0.64 3,039 13.95 0.0683
2017-08-08 2017-06-30 13F IRON MTN INC COM 46284V101 77,621 159 0.21 2,667 -3.47 0.0622
2017-05-11 2017-03-31 13F IRON MTN INC COM 46284V101 77,462 600 0.78 2,763 10.65 0.0661
2017-02-10 2016-12-31 13F IRON MTN INC COM 46284V101 76,862 -2,000 -2.54 2,497 -15.61 0.0628
2016-11-07 2016-09-30 13F IRON MTN INC COM 46284V101 78,862 -1,600 -1.99 2,959 -7.65 0.0766
2016-08-03 2016-06-30 13F IRON MTN INC COM 46284V101 80,462 10,500 15.01 3,204 35.08 0.0854
2016-05-10 2016-03-31 13F IRON MTN INC COM 46284V101 69,962 3,200 4.79 2,372 31.56 0.0643
2016-02-11 2015-12-31 13F IRON MTN INC COM 46284V101 66,762 3,700 5.87 1,803 -7.82 0.0489
2015-11-03 2015-09-30 13F IRON MTN INC COM 46284V101 63,062 3,600 6.05 1,956 6.13 0.0560
2015-08-11 2015-06-30 13F IRON MTN INC COM 46284V101 59,462 26,400 79.85 1,843 52.82 0.0490
2015-05-14 2015-03-31 13F IRON MTN INC COM 46284V101 33,062 500 1.54 1,206 -4.21 0.0317
2015-02-11 2014-12-31 13F IRON MTN COM 462846106 32,562 3,004 10.16 1,259 30.47 0.0346
2014-11-06 2014-09-30 13F IRON MTN COM 462846106 29,558 -100 -0.34 965 -8.18 0.0277
2014-08-08 2014-06-30 13F IRON MTN COM 462846106 29,658 -800 -2.63 1,051 25.12 0.0301
2014-05-08 2014-03-31 13F IRON MTN COM 462846106 30,458 200 0.66 840 -8.50 0.0242
2014-02-05 2013-12-31 13F IRON MTN COM 462846106 30,258 0 0.00 918 12.22 0.0272
2013-11-06 2013-09-30 13F IRON MTN COM 462846106 30,258 -300 -0.98 818 0.62 0.0265
2013-08-02 2013-06-30 13F IRON MTN COM 462846106 30,558 30,558 813 0.0275
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.