아이언마운틴 법인
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionDaiwa Securities Group Inc.
Latest Disclosed Ownership3,107,440 shares
Latest Disclosed Value $ 317,393,921
Daiwa Securities Group Inc. reports 14.96% decrease in ownership of IRM1 / Iron Mountain Incorporated

On May 13, 2026 - Daiwa Securities Group Inc. filed a 13F-HR form disclosing ownership of 3,107,440 shares of Iron Mountain Incorporated (MX:IRM1) valued at $317,393,921 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 3,654,086 shares of Iron Mountain Incorporated. This represents a change in shares of -14.96% 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)
2026-05-13 2026-03-31 13F IRON MTN INC DEL COM 46284V101 3,107,440 -546,646 -14.96 317,394 104,650.17 0.5355
2026-02-10 2025-12-31 13F IRON MTN INC DEL COM 46284V101 3,654,086 502,998 15.96 303 -5.61 0.9683
2025-11-14 2025-09-30 13F IRON MTN INC DEL COM 46284V101 3,151,088 196,161 6.64 321 5.94 1.0840
2025-08-14 2025-06-30 13F IRON MTN INC DEL COM 46284V101 2,954,927 202,460 7.36 303 28.39 1.1187
2025-05-13 2025-03-31 13F IRON MTN INC DEL COM 46284V101 2,752,467 -194,654 -6.60 237 -23.62 1.0012
2025-02-07 2024-12-31 13F IRON MTN INC DEL COM 46284V101 2,947,121 -179,438 -5.74 310 -16.71 1.3833
2024-11-12 2024-09-30 13F IRON MTN INC DEL COM 46284V101 3,126,559 -1,391,140 -30.79 372 -8.17 1.7162
2024-08-07 2024-06-30 13F IRON MTN COM 46284V101 4,517,699 -44,466 -0.97 405 10.68 2.1538
2024-05-02 2024-03-31 13F IRON MTN COM 46284V101 4,562,165 475,849 11.64 366 28.07 2.0650
2024-01-31 2023-12-31 13F IRON MTN COM 46284V101 4,086,316 1,546,592 60.90 286 90.00 1.7787
2023-11-01 2023-09-30 13F IRON MTN COM 46284V101 2,539,724 672,684 36.03 151 41.51 1.0757
2023-07-31 2023-06-30 13F IRON MTN COM 46284V101 1,867,040 1,753,325 1,541.86 106 1,666.67 0.7015
2023-05-02 2023-03-31 13F IRON MTN COM 46284V101 113,715 11,165 10.89 6 20.00 0.0418
2023-02-06 2022-12-31 13F IRON MTN COM 46284V101 102,550 -77 -0.08 5 -99.89 0.0393
2022-11-02 2022-09-30 13F IRON MTN COM 46284V101 102,627 456 0.45 4,513 -9.29 0.0375
2022-08-09 2022-06-30 13F IRON MTN COM 46284V101 102,171 -5,169 -4.82 4,975 -16.36 0.0380
2022-04-29 2022-03-31 13F IRON MTN COM 46284V101 107,340 -1,895 -1.73 5,948 4.06 0.0275
2022-02-03 2021-12-31 13F IRON MTN INC COM 46284V101 109,235 7,696 7.58 5,716 29.56 0.0336
2021-11-05 2021-09-30 13F IRON MTN COM 46284V101 101,539 1,049 1.04 4,412 3.74 0.0290
2021-08-06 2021-06-30 13F IRON MTN COM 46284V101 100,490 1,542 1.56 4,253 16.14 0.0286
2021-05-03 2021-03-31 13F IRON MTN COM 46284V101 98,948 5,700 6.11 3,662 33.21 0.0273
2021-02-04 2020-12-31 13F IRON MTN COM 46284V101 93,248 9,514 11.36 2,749 22.56 0.0212
2020-11-02 2020-09-30 13F IRON MTN COM 46284V101 83,734 11,415 15.78 2,243 30.33 0.0203
2020-08-11 2020-06-30 13F IRON MTN COM 46284V101 72,319 0 0.00 1,721 0.00 0.0363
2020-05-14 2020-03-31 13F IRON MTN COM 46284V101 72,319 5,800 8.72 1,721 -18.82 0.0179
2020-01-31 2019-12-31 13F IRON MTN COM 46284V101 66,519 4,000 6.40 2,120 4.69 0.0175
2019-11-04 2019-09-30 13F IRON MTN COM 46284V101 62,519 -1,371,326 -95.64 2,025 -95.49 0.0172
2019-07-24 2019-06-30 13F IRON MTN COM 46284V101 1,433,845 -1,859,738 -56.47 44,879 -61.57 0.3965
2019-04-26 2019-03-31 13F IRON MTN COM 46284V101 3,293,583 -630,265 -16.06 116,790 -8.16 1.0203
2019-02-05 2018-12-31 13F IRON MTN COM 46284V101 3,923,848 3,862,815 6,329.06 127,172 5,935.69 1.2199
2018-11-01 2018-09-30 13F IRON MTN COM 46284V101 61,033 1,210 2.02 2,107 0.62 0.0176
2018-07-30 2018-06-30 13F IRON MTN COM 46284V101 59,823 5,150 9.42 2,094 16.53 0.0165
2018-05-02 2018-03-31 13F IRON MTN COM 46284V101 54,673 8,300 17.90 1,797 2.69 0.0144
2018-02-06 2017-12-31 13F IRON MTN COM 46284V101 46,373 -2,502 -5.12 1,750 -7.94 0.0124
2017-11-02 2017-09-30 13F IRON MTN COM 46284V101 48,875 19,247 64.96 1,901 86.74 0.0130
2017-07-28 2017-06-30 13F IRON MTN COM 46284V101 29,628 3,700 14.27 1,018 10.05 0.0066
2017-05-02 2017-03-31 13F IRON MTN COM 46284V101 25,928 5,100 24.49 925 36.83 0.0058
2017-02-01 2016-12-31 13F IRON MTN COM 46284V101 20,828 5,900 39.52 676 20.71 0.0043
2017-01-10 2016-09-30 13F/A-1 IRON MTN COM 46284V101 14,928 400 2.75 560 -3.28 0.0033
2016-11-04 2016-09-30 13F IRON MTN COM 46284V101 14,928 560
2016-07-25 2016-06-30 13F IRON MTN COM 46284V101 14,528 3,100 27.13 579 49.23 0.0035
2016-05-12 2016-03-31 13F IRON MTN COM 46284V101 11,428 900 8.55 388 36.62 0.0025
2016-02-04 2015-12-31 13F IRON MTN COM 46284V101 10,528 200 1.94 284 -11.25 0.0019
2015-11-10 2015-09-30 13F IRON MTN COM 46284V101 10,328 100 0.98 320 0.95 0.0023
2015-08-05 2015-06-30 13F IRON MTN COM 46284V101 10,228 -300 -2.85 317 -17.45 0.0023
2015-05-12 2015-03-31 13F IRON MTN COM 46284V101 10,528 700 7.12 384 1.05 0.0026
2015-02-13 2014-12-31 13F IRON MTN COM 462846106 9,828 1,051 11.97 380 32.40 0.0027
2014-11-12 2014-09-30 13F IRON MTN COM 462846106 8,777 3,900 79.97 287 65.90 0.0022
2014-08-13 2014-06-30 13F/A-1 IRON MTN COM 462846106 4,877 0 0.00 173 29.10 0.0013
2014-08-13 2014-06-30 13F IRON MTN COM 462846106 4,877 173
2014-05-14 2014-03-31 13F/A-1 IRON MTN COM 462846106 4,877 0 134 0.0010
2014-05-15 2014-03-31 13F/A-2 IRON MTN COM 462846106 4,877 0 0.00 134 -9.46 0.0010
2014-05-13 2014-03-31 13F IRON MTN COM 462846106 4,877 134
2014-02-13 2013-12-31 13F IRON MTN COM 462846106 4,877 0 0.00 148 12.12 0.0013
2013-11-14 2013-09-30 13F IRON MTN COM 462846106 4,877 0 0.00 132 1.54 0.0011
2013-08-16 2013-06-30 13F/A-1 IRON MTN COM 462846106 4,877 4,877 130 0.0010
2013-08-13 2013-06-30 13F IRON MTN COM 462846106 4,877 130
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.