Iron Mountain Incorporated
US ˙ NYSE ˙ US46284V1017

SecurityIRM / Iron Mountain Incorporated
InstitutionFiduciary Trust Co
Latest Disclosed Ownership20,316 shares
Latest Disclosed Value $ 2,075,076
Fiduciary Trust Co reports 4.34% decrease in ownership of IRM / Iron Mountain Incorporated

On May 15, 2026 - Fiduciary Trust Co filed a 13F-HR form disclosing ownership of 20,316 shares of Iron Mountain Incorporated (US:IRM) valued at $2,075,076 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 21,238 shares of Iron Mountain Incorporated. This represents a change in shares of -4.34% during the quarter. The current value of the position is $2,599,432 USD.

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 20,316 -922 -4.34 2,075 17.83 0.0143
2026-02-13 2025-12-31 13F IRON MTN INC COM 46284V101 21,238 -85 -0.40 1,762 -18.96 0.0200
2025-11-14 2025-09-30 13F IRON MTN INC COM 46284V101 21,323 -1,251 -5.54 2,174 -6.13 0.0246
2025-08-14 2025-06-30 13F IRON MTN INC COM 46284V101 22,574 1,000 4.64 2,315 24.73 0.0285
2025-05-15 2025-03-31 13F IRON MTN INC COM 46284V101 21,574 -148 -0.68 1,856 -18.70 0.0243
2025-02-14 2024-12-31 13F IRON MTN INC COM 46284V101 21,722 0 0.00 2,283 -11.55 0.0301
2024-11-14 2024-09-30 13F IRON MTN INC COM 46284V101 21,722 -20 -0.09 2,581 32.49 0.0361
2024-08-14 2024-06-30 13F IRON MTN INC COM 46284V101 21,742 246 1.14 1,949 12.99 0.0293
2024-05-14 2024-03-31 13F IRON MTN INC COM 46284V101 21,496 242 1.14 1,724 15.94 0.0265
2024-02-12 2023-12-31 13F IRON MTN INC COM 46284V101 21,254 -252 -1.17 1,487 16.35 0.0249
2023-11-14 2023-09-30 13F IRON MTN INC COM 46284V101 21,506 0 0.00 1,279 4.67 0.0234
2023-08-01 2023-06-30 13F IRON MTN INC COM 46284V101 21,506 157 0.74 1,222 8.15 0.0215
2023-05-15 2023-03-31 13F IRON MTN INC COM 46284V101 21,349 -780 -3.52 1,130 2.36 0.0209
2023-02-14 2022-12-31 13F IRON MTN INC COM 46284V101 22,129 170 0.77 1,103 14.30 0.0215
2022-11-14 2022-09-30 13F IRON MTN INC COM 46284V101 21,959 -101 -0.46 965 -10.23 0.0209
2022-08-12 2022-06-30 13F IRON MTN INC COM 46284V101 22,060 120 0.55 1,075 -11.60 0.0226
2022-05-12 2022-03-31 13F IRON MTN INC COM 46284V101 21,940 1,263 6.11 1,216 12.38 0.0218
2022-02-14 2021-12-31 13F IRON MTN INC COM 46284V101 20,677 -1 -0.00 1,082 20.49 0.0178
2021-11-12 2021-09-30 13F IRON MTN INC COM 46284V101 20,678 0 0.00 898 2.63 0.0160
2021-08-16 2021-06-30 13F IRON MTN INC COM 46284V101 20,678 0 0.00 875 14.38 0.0169
2021-05-19 2021-03-31 13F IRON MTN INC COM 46284V101 20,678 -6 -0.03 765 25.41 0.0155
2021-01-26 2020-12-31 13F IRON MTN INC COM 46284V101 20,684 0 0.00 610 10.11 0.0127
2020-11-13 2020-09-30 13F IRON MTN INC COM 46284V101 20,684 -9,440 -31.34 554 -29.52 0.0131
2020-08-13 2020-06-30 13F IRON MTN INC COM 46284V101 30,124 -960 -3.09 786 6.22 0.0195
2020-05-15 2020-03-31 13F IRON MTN INC COM 46284V101 31,084 -2,710 -8.02 740 -31.29 0.0215
2020-02-04 2019-12-31 13F IRON MTN INC COM 46284V101 33,794 -10 -0.03 1,077 -1.55 0.0251
2019-11-12 2019-09-30 13F IRON MTN INC COM 46284V101 33,804 2,720 8.75 1,094 12.44 0.0275
2019-08-14 2019-06-30 13F IRON MTN INC COM 46284V101 31,084 -3 -0.01 973 -11.71 0.0255
2019-05-07 2019-03-31 13F IRON MTN INC COM 46284V101 31,087 1,503 5.08 1,102 14.91 0.0296
2019-01-29 2018-12-31 13F IRON MTN INC COM 46284V101 29,584 -13 -0.04 959 -6.16 0.0294
2018-11-13 2018-09-30 13F IRON MTN INC COM 46284V101 29,597 0 0.00 1,022 -1.45 0.0287
2018-08-03 2018-06-30 13F IRON MTN INC COM 46284V101 29,597 13 0.04 1,037 6.69 0.0314
2018-05-07 2018-03-31 13F IRON MTN INC COM 46284V101 29,584 0 0.00 972 -12.90 0.0300
2018-01-29 2017-12-31 13F IRON MTN INC COM 46284V101 29,584 0 0.00 1,116 -3.04 0.0332
2017-11-02 2017-09-30 13F IRON MTN INC COM 46284V101 29,584 0 0.00 1,151 13.29 0.0354
2017-08-09 2017-06-30 13F IRON MTN INC COM 46284V101 29,584 0 0.00 1,016 -3.70 0.0311
2017-05-15 2017-03-31 13F IRON MTN INC COM 46284V101 29,584 0 0.00 1,055 9.78 0.0322
2017-02-14 2016-12-31 13F IRON MTN INC COM 46284V101 29,584 0 0.00 961 -13.42 0.0311
2016-11-14 2016-09-30 13F IRON MTN INC COM 46284V101 29,584 0 0.00 1,110 -5.77 0.0380
2016-08-12 2016-06-30 13F IRON MTN INC COM 46284V101 29,584 0 0.00 1,178 17.45 0.0414
2016-05-16 2016-03-31 13F IRON MTN INC COM 46284V101 29,584 -1,238 -4.02 1,003 20.41 0.0355
2016-02-03 2015-12-31 13F IRON MOUNTAIN INC COMMON 46284V101 30,822 643 2.13 833 -11.00 0.0353
2015-11-10 2015-09-30 13F IRON MOUNTAIN INC COMMON 46284V101 30,179 600 2.03 936 2.07 0.0422
2015-08-10 2015-06-30 13F IRON MOUNTAIN INC Common 46284V101 29,579 0 0.00 917 -15.01 0.0382
2015-04-28 2015-03-31 13F IRON MOUNTAIN INC Common 46284V101 29,579 0 0.00 1,079 -5.60 0.0447
2015-01-26 2014-12-31 13F IRON MOUNTAIN INC (PA) COM Common 462846106 29,579 1,994 7.23 1,143 26.86 0.0480
2014-11-03 2014-09-30 13F IRON MOUNTAIN INC (PA) COM Common 462846106 27,585 0 0.00 901 -7.87 0.0397
2014-07-25 2014-06-30 13F IRON MOUNTAIN INC (PA) COM Common 462846106 27,585 0 0.00 978 28.68 0.0418
2014-05-13 2014-03-31 13F IRON MOUNTAIN INC (PA) COM Common 462846106 27,585 0 0.00 760 -9.20 0.0336
2014-02-19 2013-12-31 13F IRON MOUNTAIN INC (PA) COM Common 462846106 27,585 0 0.00 837 12.50 0.0370
2013-10-31 2013-09-30 13F/A-1 IRON MOUNTAIN INC (PA) COM Common 462846106 27,585 0 744 0.0343
2013-11-06 2013-09-30 13F/A-2 IRON MOUNTAIN INC (PA) COM Common 462846106 27,585 0 0.00 744 1.36 0.0343
2013-10-29 2013-09-30 13F IRON MOUNTAIN INC (PA) COM Common 462846106 27,585 744
2013-08-08 2013-06-30 13F IRON MOUNTAIN INC (PA) COM Common 462846106 27,585 27,585 734 0.0340
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.