Iron Mountain Incorporated
US ˙ NYSE ˙ US46284V1017

SecurityIRM / Iron Mountain Incorporated
InstitutionStrs Ohio
Latest Disclosed Ownership287,817 shares
Latest Disclosed Value $ 29,397,628
Strs Ohio reports 30.50% decrease in ownership of IRM / Iron Mountain Incorporated

On April 24, 2026 - Strs Ohio filed a 13F-HR form disclosing ownership of 287,817 shares of Iron Mountain Incorporated (US:IRM) valued at $29,397,628 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 2, 2026 disclosing 414,128 shares of Iron Mountain Incorporated. This represents a change in shares of -30.50% during the quarter. The current value of the position is $36,826,185 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)
2026-04-24 2026-03-31 13F Iron Mountain REIT 46284V101 287,817 -126,311 -30.50 29,398 -14.42 0.1166
2026-02-02 2025-12-31 13F Iron Mountain REIT 46284V101 414,128 156,613 60.82 34,352 30.86 0.1281
2025-10-30 2025-09-30 13F Iron Mountain REIT 46284V101 257,515 32,903 14.65 26,251 13.95 0.0962
2025-08-04 2025-06-30 13F Iron Mountain REIT 46284V101 224,612 33,812 17.72 23,038 40.34 0.0860
2025-05-28 2025-03-31 13F Iron Mountain REIT 46284V101 190,800 59,700 45.54 16,416 19.14 0.0688
2025-05-28 2024-12-31 13F Iron Mountain REIT 46284V101 131,100 48,300 58.33 13,780 40.04 0.0547
2024-11-01 2024-09-30 13F Iron Mountain REIT 46284V101 82,800 -69,109 -45.49 9,839 -27.73 0.0379
2024-08-05 2024-06-30 13F Iron Mountain REIT 46284V101 151,909 83,209 121.12 13,614 272,180.00 0.0538
2024-05-13 2024-03-31 13F Iron Mountain REIT 46284V101 68,700 68,700 6 0.0220
2024-01-30 2023-12-31 13F IRON MTN INC PA COM 46284V101 0 -20,589 -100.00 0 -100.00
2023-10-26 2023-09-30 13F/A-1 IRON MTN INC PA COM 46284V101 20,589 -169,300 -89.16 1 -90.00 0.0054
2023-10-26 2023-09-30 13F IRON MTN INC PA COM 46284V101 20,589 -169,300 1 0.0054
2023-07-31 2023-06-30 13F IRON MTN INC PA COM 46284V101 189,889 -139,207 -42.30 11 -41.18 0.0455
2023-08-02 2023-03-31 13F/A-2 IRON MTN INC PA COM 46284V101 329,096 -60,168 -15.46 17 -10.53 0.0754
2023-08-02 2023-03-31 13F/A-1 IRON MTN INC PA COM 46284V101 329,096 17
2023-04-27 2023-03-31 13F IRON MTN INC PA COM 46284V101 329,096 -60,168 17 0.0899
2023-01-26 2022-12-31 13F IRON MTN INC PA COM 46284V101 389,264 85,301 28.06 19 -99.86 0.0876
2022-10-27 2022-09-30 13F IRON MTN INC PA COM 46284V101 303,963 -31,855 -9.49 13,365 -18.26 0.0637
2022-07-25 2022-06-30 13F IRON MTN INC PA COM 46284V101 335,818 -10,879 -3.14 16,350 -14.89 0.0736
2022-04-21 2022-03-31 13F IRON MTN INC PA COM 46284V101 346,697 -7,682 -2.17 19,210 3.59 0.0703
2022-01-24 2021-12-31 13F IRON MTN INC PA COM 46284V101 354,379 -8,746 -2.41 18,544 17.54 0.0644
2021-10-22 2021-09-30 13F IRON MTN INC PA COM 46284V101 363,125 35,540 10.85 15,777 13.81 0.0594
2021-07-26 2021-06-30 13F IRON MTN INC PA COM 46284V101 327,585 -16,651 -4.84 13,863 8.81 0.0499
2021-04-23 2021-03-31 13F IRON MTN INC PA COM 46284V101 344,236 -27,884 -7.49 12,740 16.13 0.0480
2021-01-25 2020-12-31 13F IRON MTN INC PA COM 46284V101 372,120 -4,037 -1.07 10,970 8.86 0.0423
2020-12-14 2020-09-30 13F IRON MTN INC PA COM 46284V101 376,157 -2,868 -0.76 10,077 1.87 0.0422
2020-07-23 2020-06-30 13F IRON MTN INC PA COM 46284V101 379,025 1,189 0.31 9,892 10.01 0.0432
2020-04-23 2020-03-31 13F IRON MTN INC PA COM 46284V101 377,836 42,696 12.74 8,992 -15.81 0.0473
2020-01-24 2019-12-31 13F IRON MTN INC PA COM 46284V101 335,140 807 0.24 10,680 -1.38 0.0447
2019-10-21 2019-09-30 13F/A-1 IRON MTN INC PA COM 46284V101 334,333 -19,102 -5.40 10,829 -2.11 0.0475
2019-10-21 2019-09-30 13F IRON MTN INC PA COM 46284V101 334,333 -807 10,829 47,929.7546
2019-07-25 2019-06-30 13F IRON MTN INC PA COM 46284V101 353,435 -23,416 -6.21 11,062 -17.22 0.0492
2019-04-19 2019-03-31 13F IRON MTN INC PA COM 46284V101 376,851 -45,384 -10.75 13,363 -2.35 0.0606
2019-01-23 2018-12-31 13F IRON MTN INC PA COM 46284V101 422,235 27,447 6.95 13,684 0.41 0.0695
2018-10-19 2018-09-30 13F IRON MTN INC PA COM 46284V101 394,788 -13,001 -3.19 13,628 -4.54 0.0598
2018-08-06 2018-06-30 13F IRON MTN INC PA COM 46284V101 407,789 -21,665 -5.04 14,276 1.17 0.0615
2018-04-20 2018-03-31 13F IRON MTN INC PA COM 46284V101 429,454 57,640 15.50 14,111 0.59 0.0624
2018-01-23 2017-12-31 13F IRON MTN INC PA COM 46284V101 371,814 38,136 11.43 14,028 8.07 0.0599
2017-10-23 2017-09-30 13F IRON MTN INC PA COM 46284V101 333,678 -8,092 -2.37 12,980 10.53 0.0557
2017-07-26 2017-06-30 13F IRON MTN INC PA COM 46284V101 341,770 -25,914 -7.05 11,743 -10.46 0.0523
2017-04-26 2017-03-31 13F IRON MTN INC PA COM 46284V101 367,684 -8,875 -2.36 13,115 7.24 0.0568
2017-01-24 2016-12-31 13F IRON MTN INC PA COM 46284V101 376,559 17,310 4.82 12,230 -9.29 0.0539
2016-10-27 2016-09-30 13F IRON MTN INC PA COM 46284V101 359,249 -6,799 -1.86 13,482 -7.52 0.0602
2016-07-26 2016-06-30 13F IRON MTN INC PA COM 46284V101 366,048 79,433 27.71 14,579 50.01 0.0648
2016-04-25 2016-03-31 13F/A-1 IRON MTN INC PA COM 46284V101 286,615 -7,185 -2.45 9,719 22.48 0.0437
2016-01-28 2015-12-31 13F IRON MTN INC PA COM 46284V101 293,800 3,817 1.32 7,935 -11.78 0.0355
2015-10-21 2015-09-30 13F IRON MTN INC PA COM 46284V101 289,983 -2,280 -0.78 8,995 -0.72 0.0428
2015-08-04 2015-06-30 13F IRON MTN INC PA COM 46284V101 292,263 21,172 7.81 9,060 -8.38 0.0398
2015-04-27 2015-03-31 13F/A-1 IRON MTN INC PA COM 46284V101 271,091 271,091 9,889 0.0436
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.