Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionPrincipal Financial Group Inc
Latest Disclosed Ownership4,566,093 shares
Latest Disclosed Value $ 466,382,473
Principal Financial Group Inc reports 8.52% increase in ownership of IRM1 / Iron Mountain Incorporated

On May 4, 2026 - Principal Financial Group Inc filed a 13F-HR form disclosing ownership of 4,566,093 shares of Iron Mountain Incorporated (MX:IRM1) valued at $466,382,473 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 2, 2026 disclosing 4,207,596 shares of Iron Mountain Incorporated. This represents a change in shares of 8.52% 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)
2026-05-04 2026-03-31 13F IRON MTN INC DEL COM 46284V101 4,566,093 358,497 8.52 466,382 33.63 0.2491
2026-02-02 2025-12-31 13F IRON MTN INC DEL COM 46284V101 4,207,596 1,680,438 66.50 349,021 35.48 0.1782
2025-11-04 2025-09-30 13F IRON MTN INC DEL COM 46284V101 2,527,158 -57,698 -2.23 257,619 -2.83 0.1299
2025-08-08 2025-06-30 13F IRON MTN INC DEL COM 46284V101 2,584,856 1,680,672 185.88 265,130 240.80 0.1401
2025-04-28 2025-03-31 13F IRON MTN INC DEL COM 46284V101 904,184 488,816 117.68 77,796 78.19 0.0437
2025-01-31 2024-12-31 13F IRON MTN INC DEL COM 46284V101 415,368 62,917 17.85 43,659 4.25 0.0238
2024-10-31 2024-09-30 13F IRON MTN INC DEL COM 46284V101 352,451 11,685 3.43 41,882 37.14 0.0231
2024-07-29 2024-06-30 13F IRON MTN INC DEL COM 46284V101 340,766 -6,498 -1.87 30,539 9.64 0.0181
2024-04-29 2024-03-31 13F IRON MTN INC DEL COM 46284V101 347,264 10,011 2.97 27,854 18.03 0.0164
2024-02-07 2023-12-31 13F IRON MTN INC DEL COM 46284V101 337,253 -16,411 -4.64 23,601 12.25 0.0150
2023-11-02 2023-09-30 13F IRON MTN INC DEL COM 46284V101 353,664 9,971 2.90 21,025 7.67 0.0151
2023-08-07 2023-06-30 13F IRON MTN INC DEL COM 46284V101 343,693 -13,714 -3.84 19,529 3.27 0.0133
2023-05-09 2023-03-31 13F IRON MTN INC DEL COM 46284V101 357,407 1,651 0.46 18,910 6.63 0.0135
2023-02-09 2022-12-31 13F IRON MTN INC DEL COM 46284V101 355,756 -6,915 -1.91 17,734 11.21 0.0134
2022-11-09 2022-09-30 13F IRON MTN INC DEL COM 46284V101 362,671 -10,906 -2.92 15,947 -12.33 0.0127
2022-08-10 2022-06-30 13F IRON MTN INC COM 46284V101 373,577 14,155 3.94 18,189 -8.67 0.0135
2022-05-09 2022-03-31 13F IRON MTN INC COM 46284V101 359,422 -3,906 -1.08 19,916 4.75 0.0079
2022-05-09 2022-03-31 13F IRON MTN INC COM 46284V101 331,253 18,355
2022-02-09 2021-12-31 13F IRON MTN INC COM 46284V101 363,328 -7,571 -2.04 19,013 17.98 0.0113
2021-11-09 2021-09-30 13F IRON MTN INC COM 46284V101 370,899 6,746 1.85 16,116 4.57 0.0105
2021-08-10 2021-06-30 13F IRON MTN INC COM 46284V101 364,153 7,013 1.96 15,411 16.59 0.0100
2021-05-10 2021-03-31 13F IRON MTN INC COM 46284V101 357,140 -29,954 -7.74 13,218 15.83 0.0093
2021-02-23 2020-12-31 13F/A-1 IRON MTN INC COM 46284V101 387,094 -31,281 -7.48 11,412 1.82 0.0085
2021-02-08 2020-12-31 13F IRON MTN INC COM 46284V101 387,094 -31,281 11,412 4,489.6567
2020-11-06 2020-09-30 13F IRON MTN INC COM 46284V101 418,375 -35,037 -7.73 11,208 -5.29 0.0094
2020-08-05 2020-06-30 13F IRON MTN INC COM 46284V101 453,412 28,951 6.82 11,834 17.15 0.0105
2020-05-12 2020-03-31 13F IRON MTN INC COM 46284V101 424,461 22,815 5.68 10,102 -21.08 0.0112
2020-02-05 2019-12-31 13F IRON MTN INC COM 46284V101 401,646 -14,129 -3.40 12,800 -4.95 0.0107
2019-11-13 2019-09-30 13F IRON MTN INC COM 46284V101 415,775 1,458 0.35 13,467 3.85 0.0119
2019-08-12 2019-06-30 13F IRON MTN INC COM 46284V101 414,317 -7,072 -1.68 12,968 -13.22 0.0117
2019-05-10 2019-03-31 13F IRON MTN INC COM 46284V101 421,389 -2,020 -0.48 14,943 8.90 0.0139
2019-02-14 2018-12-31 13F IRON MTN INC COM 46284V101 423,409 -13,803 -3.16 13,722 -9.08 0.0146
2018-11-14 2018-09-30 13F IRON MTN INC COM 46284V101 437,212 18,941 4.53 15,092 3.06 0.0133
2018-08-13 2018-06-30 13F IRON MTN INC COM 46284V101 418,271 -13,402 -3.10 14,644 3.24 0.0135
2018-05-14 2018-03-31 13F IRON MTN INC COM 46284V101 431,673 6,112 1.44 14,185 -11.66 0.0136
2018-02-12 2017-12-31 13F IRON MTN INC COM 46284V101 425,561 16,002 3.91 16,057 0.78 0.0148
2017-11-02 2017-09-30 13F IRON MTN INC COM 46284V101 409,559 10,718 2.69 15,932 16.26 0.0155
2017-08-08 2017-06-30 13F IRON MTN INC COM 46284V101 398,841 18,515 4.87 13,704 1.02 0.0137
2017-05-11 2017-03-31 13F IRON MTN INC COM 46284V101 380,326 -1,268 -0.33 13,566 9.46 0.0163
2017-02-13 2016-12-31 13F IRON MTN INC COM 46284V101 381,594 -8,692 -2.23 12,394 -15.38 0.0157
2016-11-10 2016-09-30 13F IRON MTN INC COM 46284V101 390,286 12,002 3.17 14,647 -2.79 0.0193
2016-08-09 2016-06-30 13F IRON MTN INC COM 46284V101 378,284 97,671 34.81 15,067 58.35 0.0210
2016-05-10 2016-03-31 13F IRON MTN INC COM 46284V101 280,613 24 0.01 9,515 25.54 0.0138
2016-02-09 2015-12-31 13F IRON MTN INC COM 46284V101 280,589 7,243 2.65 7,579 -10.61 0.0113
2015-11-12 2015-09-30 13F/A-1 IRON MTN INC COM 46284V101 273,346 9,343 3.54 8,479 3.60 0.0133
2015-11-09 2015-09-30 13F IRON MTN INC COM 46284V101 273,346 8,479
2015-08-10 2015-06-30 13F IRON MTN INC COM 46284V101 264,003 -3,419 -1.28 8,184 -16.10 0.0122
2015-05-14 2015-03-31 13F/A-1 IRON MTN INC COM 46284V101 267,422 -2,745 -1.02 9,755 -6.61 0.0145
2015-05-12 2015-03-31 13F IRON MTN INC COM 46284V101 267,422 9,755
2015-02-12 2014-12-31 13F IRON MTN COM 462846106 270,167 64,951 31.65 10,445 55.90 0.0162
2014-11-13 2014-09-30 13F IRON MTN COM 462846106 205,216 7,005 3.53 6,700 -4.64 0.0114
2014-08-12 2014-06-30 13F IRON MTN COM 462846106 198,211 16,298 8.96 7,026 40.10 0.0118
2014-05-13 2014-03-31 13F IRON MTN COM 462846106 181,913 3,425 1.92 5,015 -7.42 0.0089
2014-02-12 2013-12-31 13F IRON MTN COM 462846106 178,488 1,431 0.81 5,417 13.23 0.0101
2013-11-05 2013-09-30 13F IRON MTN COM 462846106 177,057 -1,230,684 -87.42 4,784 -87.23 0.0099
2013-08-12 2013-06-30 13F IRON MTN COM 462846106 1,407,741 1,407,741 37,460 0.0830
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.