Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionGeode Capital Management, Llc
Latest Disclosed Ownership8,486,127 shares
Latest Disclosed Value $ 863,699,269
Geode Capital Management, Llc reports 2.33% increase in ownership of IRM1 / Iron Mountain Incorporated

On May 15, 2026 - Geode Capital Management, Llc filed a 13F-HR form disclosing ownership of 8,486,127 shares of Iron Mountain Incorporated (MX:IRM1) valued at $863,699,269 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 9, 2026 disclosing 8,292,653 shares of Iron Mountain Incorporated. This represents a change in shares of 2.33% 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 8,486,127 193,474 2.33 863,699 26.02 0.0287
2026-02-09 2025-12-31 13F IRON MOUNTAIN COM 46284V101 8,292,653 102,073 1.25 685,374 -17.60 0.0423
2025-11-12 2025-09-30 13F IRON MOUNTAIN COM 46284V101 8,190,580 103,862 1.28 831,727 0.67 0.0531
2025-08-08 2025-06-30 13F IRON MOUNTAIN COM 46284V101 8,086,718 -196,665 -2.37 826,192 15.41 0.0579
2025-05-13 2025-03-31 13F IRON MOUNTAIN COM 46284V101 8,283,383 371,274 4.69 715,894 -14.05 0.0563
2025-02-12 2024-12-31 13F IRON MOUNTAIN COM 46284V101 7,912,109 -345,856 -4.19 832,881 -14.88 0.0645
2024-11-12 2024-09-30 13F IRON MOUNTAIN COM 46284V101 8,257,965 128,622 1.58 978,479 34.24 0.0792
2024-08-09 2024-06-30 13F IRON MOUNTAIN COM 46284V101 8,129,343 808,857 11.05 728,877 24.16 0.0640
2024-05-13 2024-03-31 13F IRON MOUNTAIN COM 46284V101 7,320,486 255,710 3.62 587,069 19.03 0.0543
2024-02-13 2023-12-31 13F IRON MOUNTAIN COM 46284V101 7,064,776 -473,252 -6.28 493,198 10.26 0.0516
2023-11-13 2023-09-30 13F IRON MOUNTAIN COM 46284V101 7,538,028 145,250 1.96 447,319 6.72 0.0533
2023-08-11 2023-06-30 13F IRON MOUNTAIN COM 46284V101 7,392,778 -389,150 -5.00 419,140 1.98 0.0493
2023-05-15 2023-03-31 13F IRON MOUNTAIN COM 46284V101 7,781,928 837,623 12.06 411,015 119,034.49 0.0534
2023-02-13 2022-12-31 13F IRON MOUNTAIN COM 46284V101 6,944,305 172,801 2.55 346 -99.88 0.0485
2022-11-14 2022-09-30 13F IRON MOUNTAIN COM 46284V101 6,771,504 51,666 0.77 297,449 -8.95 0.0451
2022-08-12 2022-06-30 13F IRON MOUNTAIN COM 46284V101 6,719,838 119,228 1.81 326,681 -10.50 0.0479
2022-05-13 2022-03-31 13F IRON MOUNTAIN COM 46284V101 6,600,610 187,475 2.92 365,010 8.56 0.0456
2022-02-11 2021-12-31 13F IRON MOUNTAIN COM 46284V101 6,413,135 82,900 1.31 336,217 22.04 0.0405
2021-11-12 2021-09-30 13F IRON MOUNTAIN COM 46284V101 6,330,235 231,564 3.80 275,496 6.63 0.0371
2021-08-13 2021-06-30 13F IRON MOUNTAIN COM 46284V101 6,098,671 67,748 1.12 258,359 15.65 0.0356
2021-05-12 2021-03-31 13F IRON MOUNTAIN COM 46284V101 6,030,923 94,663 1.59 223,390 27.53 0.0342
2021-02-12 2020-12-31 13F IRON MOUNTAIN COM 46284V101 5,936,260 860,529 16.95 175,164 28.47 0.0294
2020-11-13 2020-09-30 13F IRON MOUNTAIN COM 46284V101 5,075,731 -9,758 -0.19 136,343 2.20 0.0267
2020-08-13 2020-06-30 13F IRON MOUNTAIN COM 46284V101 5,085,489 72,394 1.44 133,410 11.03 0.0285
2020-05-14 2020-03-31 13F IRON MOUNTAIN COM 46284V101 5,013,095 289,414 6.13 120,158 -20.03 0.0313
2020-02-20 2019-12-31 13F/A-1 IRON MOUNTAIN COM 46284V101 4,723,681 244,760 5.46 150,251 3.73 0.0314
2020-02-13 2019-12-31 13F IRON MOUNTAIN COM 46284V101 4,723,681 244,760 150,251 19,148.1725
2019-11-12 2019-09-30 13F IRON MOUNTAIN COM 46284V101 4,478,921 122,025 2.80 144,855 6.40 0.0338
2019-08-14 2019-06-30 13F IRON MOUNTAIN COM 46284V101 4,356,896 157,775 3.76 136,139 -8.42 0.0329
2019-05-14 2019-03-31 13F IRON MOUNTAIN COM 46284V101 4,199,121 283,921 7.25 148,657 17.35 0.0385
2019-03-06 2018-12-31 13F/A-1 IRON MOUNTAIN COM 46284V101 3,915,200 270,237 7.41 126,683 0.86 0.0392
2019-02-13 2018-12-31 13F IRON MOUNTAIN COM 46284V101 3,915,200 270,237 126,683
2018-11-13 2018-09-30 13F IRON MOUNTAIN COM 46284V101 3,644,963 154,964 4.44 125,600 2.99 0.0354
2018-08-14 2018-06-30 13F IRON MOUNTAIN COM 46284V101 3,489,999 246,714 7.61 121,950 14.68 0.0375
2018-05-15 2018-03-31 13F IRON MOUNTAIN COM 46284V101 3,243,285 202,987 6.68 106,339 -7.11 0.0346
2018-02-13 2017-12-31 13F IRON MOUNTAIN COM 46284V101 3,040,298 258,581 9.30 114,482 6.00 0.0389
2017-11-14 2017-09-30 13F IRON MOUNTAIN COM 46284V101 2,781,717 249,896 9.87 108,004 24.35 0.0399
2017-08-14 2017-06-30 13F IRON MOUNTAIN COM 46284V101 2,531,821 96,037 3.94 86,853 0.10 0.0342
2017-06-21 2017-03-31 13F/A-1 IRON MTN INC PA COM COM 46284V101 2,435,784 201,404 9.01 86,763 19.70 0.0356
2017-05-12 2017-03-31 13F IRON MTN INC PA COM COM 46284V101 2,435,784 86,763
2017-02-14 2016-12-31 13F IRON MTN INC PA COM COM 46284V101 2,234,380 154,924 7.45 72,486 -6.97 0.0337
2016-11-10 2016-09-30 13F IRON MTN INC PA COM COM 46284V101 2,079,456 139,030 7.16 77,915 1.00 0.0392
2016-08-12 2016-06-30 13F IRON MTN INC PA COM COM 46284V101 1,940,426 327,509 20.31 77,147 41.34 0.0420
2016-05-13 2016-03-31 13F IRON MTN INC PA COM COM 46284V101 1,612,917 37,165 2.36 54,584 28.51 0.0290
2016-02-12 2015-12-31 13F IRON MTN INC PA COM COM 46284V101 1,575,752 -107,745 -6.40 42,473 -18.52 0.0242
2015-11-13 2015-09-30 13F IRON MTN INC PA COM COM 46284V101 1,683,497 34,418 2.09 52,130 2.16 0.0316
2015-08-14 2015-06-30 13F IRON MTN INC PA COM COM 46284V101 1,649,079 1,649,079 51,029 0.0291
2015-05-14 2015-03-31 13F IRON MTN INC PA COM COM 462846106 0 -1,368,489 -100.00 0 -100.00
2015-02-12 2014-12-31 13F IRON MTN INC PA COM COM 462846106 1,368,489 127,685 10.29 52,838 30.59 0.0314
2014-11-14 2014-09-30 13F IRON MTN INC PA COM COM 462846106 1,240,804 -12,126 -0.97 40,460 -8.85 0.0262
2014-08-13 2014-06-30 13F IRON MTN INC PA COM COM 462846106 1,252,930 18,705 1.52 44,389 30.51 0.0287
2014-05-14 2014-03-31 13F IRON MTN INC PA COM COM 462846106 1,234,225 -22,741 -1.81 34,013 -10.82 0.0228
2014-02-14 2013-12-31 13F IRON MTN INC PA COM COM 462846106 1,256,966 26,633 2.16 38,138 14.75 0.0264
2013-11-14 2013-09-30 13F IRON MTN INC PA COM COM 462846106 1,230,333 82,435 7.18 33,236 8.83 0.0266
2013-08-14 2013-06-30 13F IRON MTN INC PA COM COM 462846106 1,147,898 1,147,898 30,539 0.0268
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.