Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionRB Capital Management, LLC
Latest Disclosed Ownership47,363 shares
Latest Disclosed Value $ 4,837,650
RB Capital Management, LLC reports 0.31% increase in ownership of IRM1 / Iron Mountain Incorporated

On May 14, 2026 - RB Capital Management, LLC filed a 13F-HR form disclosing ownership of 47,363 shares of Iron Mountain Incorporated (MX:IRM1) valued at $4,837,650 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 3, 2026 disclosing 47,216 shares of Iron Mountain Incorporated. This represents a change in shares of 0.31% 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)
2026-05-14 2026-03-31 13F IRON MTN INC DEL COM 46284V101 47,363 147 0.31 4,838 23.52 1.0277
2026-02-03 2025-12-31 13F IRON MTN INC DEL COM 46284V101 47,216 477 1.02 3,917 -17.80 0.7780
2025-10-21 2025-09-30 13F IRON MTN INC DEL COM 46284V101 46,739 1,120 2.46 4,765 1.82 0.9834
2025-07-07 2025-06-30 13F IRON MTN INC DEL COM 46284V101 45,619 521 1.16 4,679 20.59 1.0595
2025-05-14 2025-03-31 13F IRON MTN INC DEL COM 46284V101 45,098 -1,242 -2.68 3,880 -20.33 0.9000
2025-02-18 2024-12-31 13F IRON MTN INC DEL COM 46284V101 46,340 156 0.34 4,871 -11.26 1.1111
2024-11-18 2024-09-30 13F IRON MTN INC DEL COM 46284V101 46,184 -479 -1.03 5,488 31.26 1.2770
2024-08-14 2024-06-30 13F IRON MTN INC DEL COM 46284V101 46,663 701 1.53 4,182 13.43 1.0311
2024-05-13 2024-03-31 13F IRON MTN INC DEL COM 46284V101 45,962 1,372 3.08 3,687 18.14 0.9685
2024-02-06 2023-12-31 13F IRON MTN INC DEL COM 46284V101 44,590 79 0.18 3,120 17.91 0.8936
2023-11-16 2023-09-30 13F IRON MTN INC DEL COM 46284V101 44,511 -35 -0.08 2,646 4.54 0.8246
2023-12-11 2023-06-30 13F/A-1 IRON MTN INC DEL COM 46284V101 44,546 555 1.26 2,531 8.77 0.7614
2023-08-08 2023-06-30 13F IRON MTN INC DEL COM 46284V101 44,546 555 2,531 0.6502
2023-05-10 2023-03-31 13F IRON MTN INC DEL COM 46284V101 43,991 412 0.95 2,328 7.14 0.7365
2023-01-19 2022-12-31 13F/A-1 IRON MTN INC DEL COM 46284V101 43,579 366 0.85 2,172 14.32 0.7672
2023-01-11 2022-12-31 13F IRON MTN INC DEL COM 46284V101 43,579 366 2 0.7600
2022-10-24 2022-09-30 13F IRON MTN INC DEL COM 46284V101 43,213 2,702 6.67 1,900 -3.70 0.7281
2022-07-14 2022-06-30 13F IRON MTN INC COM 46284V101 40,511 1,574 4.04 1,973 -8.57 0.7353
2022-05-10 2022-03-31 13F/A-1 IRON MTN INC COM 46284V101 38,937 1,420 3.78 2,158 9.93 0.6924
2022-04-11 2022-03-31 13F IRON MTN INC COM 46284V101 38,937 1,420 2,158 0.7536
2022-02-14 2021-12-31 13F IRON MTN INC COM 46284V101 37,517 1,448 4.01 1,963 25.27 0.6126
2021-11-12 2021-09-30 13F IRON MTN INC COM 46284V101 36,069 662 1.87 1,567 4.61 0.5890
2021-08-06 2021-06-30 13F/A-1 IRON MTN INC COM 46284V101 35,407 2,141 6.44 1,498 21.69 0.5657
2021-08-06 2021-06-30 13F IRON MTN INC COM 46284V101 35,407 2,141 1,498 0.3679
2021-05-11 2021-03-31 13F IRON MTN INC COM 46284V101 33,266 1,411 4.43 1,231 31.10 0.5430
2021-02-04 2020-12-31 13F IRON MTN INC COM 46284V101 31,855 1,500 4.94 939 13.13 0.4336
2020-11-12 2020-09-30 13F IRON MTN INC COM 46284V101 30,355 7,266 31.47 830 37.65 0.3901
2020-07-31 2020-06-30 13F IRON MTN INC COM 46284V101 23,089 4,965 27.39 603 54.62 0.3196
2020-05-15 2020-03-31 13F IRON MTN INC COM 46284V101 18,124 1,208 7.14 390 -24.71 0.2506
2020-02-11 2019-12-31 13F IRON MTN INC COM 46284V101 16,916 4,007 31.04 518 24.22 0.2956
2019-10-10 2019-09-30 13F/A-1 IRON MTN INC COM 46284V101 12,909 12,909 417 0.2676
2019-10-10 2019-09-30 13F IRON MTN INC COM 46284V101 12,909 417 0.2676
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.