Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionAtlantic Union Bankshares Corp
Latest Disclosed Ownership8,628 shares
Latest Disclosed Value $ 881,287
Atlantic Union Bankshares Corp reports 6.92% decrease in ownership of IRM1 / Iron Mountain Incorporated

On May 12, 2026 - Atlantic Union Bankshares Corp filed a 13F-HR form disclosing ownership of 8,628 shares of Iron Mountain Incorporated (MX:IRM1) valued at $881,287 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 4, 2026 disclosing 9,269 shares of Iron Mountain Incorporated. This represents a change in shares of -6.92% 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)
2026-05-12 2026-03-31 13F IRON MTN INC DEL COM 46284V101 8,628 -641 -6.92 881 14.71 0.0064
2026-02-04 2025-12-31 13F IRON MTN INC DEL COM 46284V101 9,269 -193 -2.04 769 -20.33 0.0144
2025-11-04 2025-09-30 13F IRON MTN INC DEL COM 46284V101 9,462 541 6.06 965 5.36 0.0182
2025-08-06 2025-06-30 13F IRON MTN INC DEL COM 46284V101 8,921 909 11.35 915 32.80 0.0209
2025-05-05 2025-03-31 13F IRON MTN INC DEL COM REIT 46284V101 8,012 -159 -1.95 689 -19.70 0.0417
2025-02-07 2024-12-31 13F IRON MTN INC DEL COM REIT 46284V101 8,171 0 0.00 859 -11.55 0.0500
2024-11-14 2024-09-30 13F IRON MTN INC DEL COM REIT 46284V101 8,171 -250 -2.97 971 28.65 0.0564
2024-07-24 2024-06-30 13F IRON MTN INC DEL COM REIT 46284V101 8,421 0 0.00 755 11.70 0.0471
2024-04-16 2024-03-31 13F IRON MTN INC DEL COM REIT 46284V101 8,421 -673 -7.40 675 6.13 0.0569
2024-01-19 2023-12-31 13F IRON MTN INC DEL COM REIT 46284V101 9,094 -700 -7.15 636 9.28 0.0590
2023-10-20 2023-09-30 13F IRON MTN INC DEL COM REIT 46284V101 9,794 0 0.00 582 4.68 0.0597
2023-07-11 2023-06-30 13F IRON MTN INC DEL COM REIT 46284V101 9,794 0 0.00 556 7.34 0.0555
2023-05-08 2023-03-31 13F IRON MTN INC DEL COM REIT 46284V101 9,794 0 0.00 518 6.15 0.0539
2023-02-09 2022-12-31 13F IRON MTN INC DEL COM REIT 46284V101 9,794 0 0.00 488 13.23 0.0522
2022-10-25 2022-09-30 13F IRON MTN INC DEL COM REIT 46284V101 9,794 -146 -1.47 431 -10.95 0.0495
2022-07-21 2022-06-30 13F IRON MTN INC NEW COM REIT 46284V101 9,940 0 0.00 484 -12.16 0.0495
2022-04-26 2022-03-31 13F IRON MTN INC NEW COM REIT 46284V101 9,940 0 0.00 551 5.96 0.0482
2022-01-19 2021-12-31 13F IRON MTN INC NEW COM REIT 46284V101 9,940 -50 -0.50 520 19.82 0.0441
2021-10-26 2021-09-30 13F IRON MTN INC NEW COM REIT 46284V101 9,990 -100 -0.99 434 1.64 0.0409
2021-07-26 2021-06-30 13F IRON MTN INC NEW COM REIT 46284V101 10,090 -637 -5.94 427 7.56 0.0412
2021-05-04 2021-03-31 13F IRON MTN INC NEW COM REIT 46284V101 10,727 533 5.23 397 31.89 0.0405
2021-02-01 2020-12-31 13F IRON MTN INC COM 46284V101 10,194 398 4.06 301 14.89 0.0313
2020-10-16 2020-09-30 13F IRON MTN INC COM 46284V101 9,796 -13,523 -57.99 262 -56.98 0.0305
2020-07-15 2020-06-30 13F IRON MTN INC COM 46284V101 23,319 -460 -1.93 609 7.60 0.0759
2020-04-10 2020-03-31 13F IRON MTN INC COM 46284V101 23,779 -594 -2.44 566 -27.16 0.0826
2020-01-14 2019-12-31 13F IRON MOUNTAIN COM 46284V101 24,373 -130 -0.53 777 -2.14 0.0996
2019-10-17 2019-09-30 13F IRON MOUNTAIN COM 46284V101 24,503 1,461 6.34 794 10.12 0.1063
2019-07-23 2019-06-30 13F IRON MOUNTAIN COM 46284V101 23,042 23,042 721 0.0968
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.