Iron Mountain Incorporated
US ˙ NYSE ˙ US46284V1017

SecurityIRM / Iron Mountain Incorporated
InstitutionAdvisory Services Network, LLC
Latest Disclosed Ownership12,356 shares
Latest Disclosed Value $ 1,262,064
Advisory Services Network, LLC reports 5.39% increase in ownership of IRM / Iron Mountain Incorporated

On May 15, 2026 - Advisory Services Network, LLC filed a 13F-HR form disclosing ownership of 12,356 shares of Iron Mountain Incorporated (US:IRM) valued at $1,262,042 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 11,724 shares of Iron Mountain Incorporated. This represents a change in shares of 5.39% during the quarter. The current value of the position is $1,580,950 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 REIT 46284V101 12,356 632 5.39 1,262 29.84 0.0117
2026-02-17 2025-12-31 13F IRON MTN INC DEL COM REIT 46284V101 11,724 -425 -3.50 972 -21.49 0.0138
2025-11-18 2025-09-30 13F IRON MTN INC DEL REIT 46284V101 12,149 485 4.16 1,239 9.07 0.0182
2025-08-19 2025-06-30 13F IRON MTN INC DEL REIT 46284V101 11,664 -352 -2.93 1,136 9.87 0.0183
2025-05-15 2025-03-31 13F IRON MTN INC DEL REIT 46284V101 12,016 -16,280 -57.53 1,034 -65.27 0.0199
2025-02-13 2024-12-31 13F IRON MTN INC DEL REIT 46284V101 28,296 1,575 5.89 2,974 24.23 0.0554
2024-11-14 2024-09-30 13F IRON MTN INC DEL REIT 46284V101 26,721 0 0.00 2,395 0.00 0.0495
2024-08-13 2024-06-30 13F IRON MTN INC DEL REIT 46284V101 26,721 1,437 5.68 2,395 18.05 0.0495
2024-05-06 2024-03-31 13F IRON MTN INC DEL REIT 46284V101 25,284 2,026 8.71 2,028 24.65 0.0450
2024-02-09 2023-12-31 13F IRON MTN INC DEL REIT 46284V101 23,258 -3,033 -11.54 1,628 4.09 0.0398
2023-11-14 2023-09-30 13F IRON MTN INC DEL REIT 46284V101 26,291 1,118 4.44 1,563 9.30 0.0420
2023-08-09 2023-06-30 13F IRON MTN INC DEL REIT 46284V101 25,173 -486 -1.89 1,430 5.38 0.0381
2023-05-17 2023-03-31 13F IRON MTN INC DEL REIT 46284V101 25,659 341 1.35 1,358 7.53 0.0376
2023-02-13 2022-12-31 13F IRON MTN INC DEL REIT 46284V101 25,318 -410 -1.59 1,262 11.48 0.0387
2022-11-14 2022-09-30 13F IRON MTN INC DEL REIT 46284V101 25,728 -722 -2.73 1,132 -12.04 0.0400
2022-08-02 2022-06-30 13F IRON MTN INC REIT 46284V101 26,450 802 3.13 1,287 -9.43 0.0440
2022-05-23 2022-03-31 13F IRON MTN INC REIT 46284V101 25,648 -9,416 -26.85 1,421 -22.56 0.0418
2022-02-14 2021-12-31 13F IRON MTN INC REIT 46284V101 35,064 -18,013 -33.94 1,835 -20.42 0.0528
2021-11-05 2021-09-30 13F IRON MTN INC REIT 46284V101 53,077 -32,024 -37.63 2,306 -35.96 0.0733
2021-08-12 2021-06-30 13F IRON MTN INC REIT 46284V101 85,101 17,832 26.51 3,601 44.62 0.1136
2021-05-24 2021-03-31 13F IRON MTN INC REIT 46284V101 67,269 56,195 507.45 2,490 663.80 0.0925
2021-02-09 2020-12-31 13F IRON MTN INC REIT 46284V101 11,074 -250 -2.21 326 7.24 0.0131
2020-11-16 2020-09-30 13F IRON MTN INC REIT 46284V101 11,324 3,425 43.36 304 47.57 0.0143
2020-08-10 2020-06-30 13F IRON MOUNTAIN REIT 46284V101 7,899 -42 -0.53 206 8.99 0.0113
2020-05-15 2020-03-31 13F IRON MTN INC REIT 46284V101 7,941 -686 -7.95 189 -31.27 0.0124
2020-02-04 2019-12-31 13F IRON MTN INC REIT 46284V101 8,627 6,965 419.07 275 428.85 0.0145
2019-11-04 2019-09-30 13F IRON MTN INC REIT 46284V101 1,662 0 0.00 52 0.00 0.0032
2019-08-01 2019-06-30 13F IRON MTN INC REIT 46284V101 1,662 22 1.34 52 -11.86 0.0032
2019-05-20 2019-03-31 13F IRON MTN INC REIT 46284V101 1,640 -19,433 -92.22 59 -91.36 0.0041
2019-02-15 2018-12-31 13F IRON MTN INC REIT 46284V101 21,073 676 3.31 683 -2.98 0.0596
2018-11-02 2018-09-30 13F IRON MTN INC REIT 46284V101 20,397 1,028 5.31 704 2.47 0.0514
2018-07-27 2018-06-30 13F IRON MTN INC REIT 46284V101 19,369 -292 -1.49 687 6.35 0.0523
2018-04-23 2018-03-31 13F IRON MTN INC REIT 46284V101 19,661 2,792 16.55 646 1.57 0.0516
2018-02-08 2017-12-31 13F IRON MTN INC REIT 46284V101 16,869 13,230 363.56 636 347.89 0.0554
2017-10-12 2017-09-30 13F IRON MTN INC REIT 46284V101 3,639 2,140 142.76 142 173.08 0.0163
2017-08-17 2017-06-30 13F IRON MTN INC NEW COM REIT 46284V101 1,499 -120 -7.41 52 -10.34 0.0068
2017-04-28 2017-03-31 13F IRON MTN INC NEW COM REIT 46284V101 1,619 93 6.09 58 1.75 0.0084
2016-10-07 2016-09-30 13F IRON MTN INC REIT 46284V101 1,526 48 3.25 57 -3.39 0.0107
2016-07-27 2016-06-30 13F IRON MTN INC REIT 46284V101 1,478 99 7.18 59 25.53 0.0134
2016-04-21 2016-03-31 13F IRON MTN INC REIT 46284V101 1,379 2 0.15 47 27.03 0.0128
2016-01-27 2015-12-31 13F IRON MTN INC NEW COM REIT 46284V101 1,377 2 0.15 37 -13.95 0.0119
2015-10-01 2015-09-30 13F IRON MOUNTAIN REIT 46284V101 1,375 213 18.33 43 19.44 0.0130
2015-07-02 2015-06-30 13F IRON MOUNTAIN REIT 46284V101 1,162 1,098 1,715.62 36 1,700.00 0.0106
2015-04-08 2015-03-31 13F IRON MTN INC NEW COM REIT 46284V101 64 0 0.00 2 -33.33 0.0006
2015-01-23 2014-12-31 13F IRON MTN INC COM REIT 462846106 64 -159 -71.30 3 -57.14 0.0009
2014-02-13 2013-12-31 13F IRON MTN Stock 462846106 223 223 7 0.0035
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.