Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionAmeriprise Financial Inc
Latest Disclosed Ownership1,851,007 shares
Latest Disclosed Value $ 189,082,930
Ameriprise Financial Inc reports 6.11% increase in ownership of IRM1 / Iron Mountain Incorporated

On May 15, 2026 - Ameriprise Financial Inc filed a 13F-HR form disclosing ownership of 1,851,007 shares of Iron Mountain Incorporated (MX:IRM1) valued at $189,082,930 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 1,744,405 shares of Iron Mountain Incorporated. This represents a change in shares of 6.11% 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 1,851,007 106,602 6.11 189,083 32.72 0.0081
2026-02-17 2025-12-31 13F IRON MOUNTAIN COM 46284V101 1,744,405 38,373 2.25 142,473 -18.02 0.0322
2025-11-14 2025-09-30 13F IRON MOUNTAIN COM 46284V101 1,706,032 208 0.01 173,782 -1.22 0.0399
2025-08-14 2025-06-30 13F IRON MOUNTAIN COM 46284V101 1,705,824 151,140 9.72 175,931 32.89 0.0434
2025-05-14 2025-03-31 13F IRON MOUNTAIN COM 46284V101 1,554,684 -35,686 -2.24 132,388 -20.85 0.0357
2025-02-14 2024-12-31 13F IRON MOUNTAIN COM 46284V101 1,590,370 -105,528 -6.22 167,263 -18.12 0.0429
2024-11-14 2024-09-30 13F IRON MOUNTAIN COM 46284V101 1,695,898 286,407 20.32 204,280 60.53 0.0524
2024-08-14 2024-06-30 13F IRON MOUNTAIN COM 46284V101 1,409,491 -62,455 -4.24 127,250 7.03 0.0344
2024-05-15 2024-03-31 13F IRON MOUNTAIN COM 46284V101 1,471,946 -123,720 -7.75 118,887 5.85 0.0327
2024-02-14 2023-12-31 13F IRON MOUNTAIN COM 46284V101 1,595,666 -132,147 -7.65 112,318 8.26 0.0336
2023-11-14 2023-09-30 13F IRON MOUNTAIN COM 46284V101 1,727,813 1,178,754 214.69 103,744 232.18 0.0341
2023-08-14 2023-06-30 13F IRON MOUNTAIN COM 46284V101 549,059 -131,028 -19.27 31,232 -13.37 0.0098
2023-05-22 2023-03-31 13F/A-1 IRON MOUNTAIN COM 46284V101 680,087 131,454 23.96 36,050 31.71 0.0118
2023-05-15 2023-03-31 13F IROBOT COM 46284V101 680,087 131,454 36,050 0.0022
2023-02-14 2022-12-31 13F IRON MOUNTAIN COM 46284V101 548,633 63,561 13.10 27,370 28.09 0.0094
2022-11-14 2022-09-30 13F IRON MOUNTAIN COM 46284V101 485,072 7,092 1.48 21,368 -8.26 0.0079
2022-08-15 2022-06-30 13F IRON MOUNTAIN COM 46284V101 477,980 -36,991 -7.18 23,293 -18.37 0.0081
2022-05-16 2022-03-31 13F IRON MOUNTAIN COM 46284V101 514,971 20,160 4.07 28,535 10.26 0.0084
2022-02-14 2021-12-31 13F IRON MOUNTAIN COM 46284V101 494,811 -74,381 -13.07 25,880 4.51 0.0072
2021-11-15 2021-09-30 13F IRON MOUNTAIN COM 46284V101 569,192 83,213 17.12 24,763 20.35 0.0079
2021-08-16 2021-06-30 13F IRON MOUNTAIN COM 46284V101 485,979 -74,819 -13.34 20,575 -0.96 0.0064
2021-05-17 2021-03-31 13F IRON MOUNTAIN COM 46284V101 560,798 21,724 4.03 20,775 30.41 0.0069
2021-02-12 2020-12-31 13F IRON MOUNTAIN COM 46284V101 539,074 -179,798 -25.01 15,931 -17.34 0.0057
2020-11-16 2020-09-30 13F IRON MOUNTAIN COM 46284V101 718,872 -1,045,099 -59.25 19,274 -59.04 0.0078
2020-08-14 2020-06-30 13F IRON MOUNTAIN COM 46284V101 1,763,971 -58,952 -3.23 47,050 9.58 0.0202
2020-05-15 2020-03-31 13F IRON MOUNTAIN COM 46284V101 1,822,923 -1,803,545 -49.73 42,936 -63.45 0.0225
2020-02-14 2019-12-31 13F IRON MOUNTAIN COM 46284V101 3,626,468 -166,195 -4.38 117,460 -4.85 0.0488
2019-11-14 2019-09-30 13F IRON MOUNTAIN COM 46284V101 3,792,663 373,438 10.92 123,453 15.99 0.0553
2019-08-14 2019-06-30 13F IRON MOUNTAIN COM 46284V101 3,419,225 796,843 30.39 106,436 14.22 0.0477
2019-05-15 2019-03-31 13F IRON MOUNTAIN COM 46284V101 2,622,382 1,011,103 62.75 93,184 78.22 0.0429
2019-02-14 2018-12-31 13F IRON MOUNTAIN COM 46284V101 1,611,279 64,392 4.16 52,286 -1.49 0.0261
2018-11-14 2018-09-30 13F IRON MOUNTAIN COM 46284V101 1,546,887 1,054,990 214.47 53,077 208.05 0.0186
2018-08-14 2018-06-30 13F IRON MOUNTAIN COM 46284V101 491,897 -31,225 -5.97 17,230 0.17 0.0076
2018-05-14 2018-03-31 13F IRON MOUNTAIN COM 46284V101 523,122 18,394 3.64 17,200 -9.72 0.0078
2018-02-12 2017-12-31 13F IRON MOUNTAIN COM 46284V101 504,728 234,463 86.75 19,052 81.07 0.0087
2017-11-07 2017-09-30 13F IRON MOUNTAIN COM 46284V101 270,265 98,091 56.97 10,522 82.48 0.0050
2017-08-10 2017-06-30 13F IRON MOUNTAIN COM 46284V101 172,174 -843 -0.49 5,766 -6.70 0.0029
2017-05-05 2017-03-31 13F IRON MOUNTAIN COM 46284V101 173,017 22,227 14.74 6,180 26.28 0.0032
2017-02-03 2016-12-31 13F IRON MOUNTAIN COM 46284V101 150,790 -130,942 -46.48 4,894 -53.72 0.0027
2016-11-08 2016-09-30 13F IRON MOUNTAIN COM 46284V101 281,732 20,601 7.89 10,575 1.75 0.0059
2016-08-08 2016-06-30 13F IRON MOUNTAIN COM 46284V101 261,131 -79,018 -23.23 10,393 -10.15 0.0061
2016-05-12 2016-03-31 13F IRON MOUNTAIN COM 46284V101 340,149 -75,402 -18.15 11,567 3.06 0.0069
2016-02-11 2015-12-31 13F IRON MOUNTAIN COM 46284V101 415,551 -11,612 -2.72 11,224 -15.30 0.0066
2015-11-12 2015-09-30 13F IRON MOUNTAIN COM 46284V101 427,163 -283,638 -39.90 13,251 -39.86 0.0082
2015-08-13 2015-06-30 13F IRON MOUNTAIN COM 46284V101 710,801 328,890 86.12 22,034 58.30 0.0125
2015-05-14 2015-03-31 13F IRON MOUNTAIN COM 46284V101 381,911 7,729 2.07 13,919 -3.78 0.0080
2015-02-13 2014-12-31 13F IRON MOUNTAIN COM 462846106 374,182 -2,977 -0.79 14,466 16.91 0.0084
2014-11-14 2014-09-30 13F IRON MOUNTAIN COM 462846106 377,159 -122,675 -24.54 12,374 -30.19 0.0074
2014-08-13 2014-06-30 13F IRON MOUNTAIN COM 462846106 499,834 -4,206 -0.83 17,724 27.51 0.0105
2014-05-14 2014-03-31 13F IRON MOUNTAIN COM 462846106 504,040 72,108 16.69 13,900 5.99 0.0083
2014-02-14 2013-12-31 13F IRON MOUNTAIN COM 462846106 431,932 49,595 12.97 13,114 26.89 0.0079
2013-11-14 2013-09-30 13F IRON MOUNTAIN COM 462846106 382,337 -14,165 -3.57 10,335 -2.08 0.0068
2013-08-14 2013-06-30 13F IRON MOUNTAIN COM 462846106 396,502 396,502 10,555 0.0073
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.