Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionRoman Butler Fullerton & Co
Latest Disclosed Ownership12,330 shares
Latest Disclosed Value $ 1,318,949
Roman Butler Fullerton & Co reports 0.42% decrease in ownership of IRM1 / Iron Mountain Incorporated

On April 30, 2026 - Roman Butler Fullerton & Co filed a 13F-HR form disclosing ownership of 12,330 shares of Iron Mountain Incorporated (MX:IRM1) valued at $1,318,949 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 12,382 shares of Iron Mountain Incorporated. This represents a change in shares of -0.42% 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)
2026-04-30 2026-03-31 13F IRON MTN INC DEL COM 46284V101 12,330 -52 -0.42 1,319 13.43 0.3627
2026-01-26 2025-12-31 13F IRON MTN INC DEL COM 46284V101 12,382 -468 -3.64 1,162 -10.75 0.3047
2025-11-06 2025-09-30 13F IRON MTN INC DEL COM 46284V101 12,850 29 0.23 1,302 2.28 0.3494
2025-07-30 2025-06-30 13F IRON MTN INC DEL COM 46284V101 12,821 -40 -0.31 1,274 18.86 0.3754
2025-04-21 2025-03-31 13F IRON MTN INC DEL COM 46284V101 12,861 -789 -5.78 1,071 -24.52 0.4159
2025-01-30 2024-12-31 13F IRON MTN INC DEL COM 46284V101 13,650 -330 -2.36 1,419 -16.77 0.4504
2024-10-29 2024-09-30 13F IRON MTN INC DEL COM 46284V101 13,980 15 0.11 1,706 28.39 0.5132
2024-07-15 2024-06-30 13F IRON MTN INC DEL COM 46284V101 13,965 -966 -6.47 1,329 17.31 0.4298
2024-04-29 2024-03-31 13F IRON MTN INC DEL COM 46284V101 14,931 -1,462 -8.92 1,133 2.26 0.4246
2024-01-31 2023-12-31 13F IRON MTN INC DEL COM 46284V101 16,393 -458 -2.72 1,108 8.96 0.4310
2023-10-18 2023-09-30 13F IRON MTN INC DEL COM 46284V101 16,851 -373 -2.17 1,016 -5.14 0.4796
2023-07-25 2023-06-30 13F IRON MTN INC DEL COM 46284V101 17,224 106 0.62 1,072 15.41 0.4919
2023-04-27 2023-03-31 13F IRON MTN INC DEL COM 46284V101 17,118 -404 -2.31 929 1.31 0.4620
2023-01-23 2022-12-31 13F IRON MTN INC DEL COM 46284V101 17,522 -452 -2.51 917 10.76 0.4743
2022-10-17 2022-09-30 13F IRON MTN INC DEL COM 46284V101 17,974 -58 -0.32 827 2.22 0.5259
2022-07-26 2022-06-30 13F IRON MTN INC COM 46284V101 18,032 53 0.29 809 -18.78 0.4492
2022-05-05 2022-03-31 13F IRON MTN INC COM 46284V101 17,979 -3,986 -18.15 996 -13.32 0.4608
2022-01-24 2021-12-31 13F IRON MTN INC COM 46284V101 21,965 -972 -4.24 1,149 11.34 0.5076
2021-11-10 2021-09-30 13F IRON MTN INC COM 46284V101 22,937 515 2.30 1,032 8.75 0.4816
2021-07-29 2021-06-30 13F IRON MTN INC COM 46284V101 22,422 0 0.00 949 10.99 0.4618
2021-04-22 2021-03-31 13F IRON MTN INC COM 46284V101 22,422 1,597 7.67 855 39.25 0.4276
2021-02-01 2020-12-31 13F IRON MTN INC COM 46284V101 20,825 1,138 5.78 614 16.51 0.3625
2020-10-15 2020-09-30 13F IRON MTN INC COM 46284V101 19,687 12 0.06 527 2.53 0.3447
2020-07-28 2020-06-30 13F IRON MTN INC COM 46284V101 19,675 196 1.01 514 10.78 0.3666
2020-04-13 2020-03-31 13F IRON MTN INC COM 46284V101 19,479 -2,408 -11.00 464 -33.52 0.4095
2020-01-27 2019-12-31 13F IRON MTN INC COM 46284V101 21,887 -1,046 -4.56 698 -6.06 0.4605
2019-10-15 2019-09-30 13F IRON MTN INC COM 46284V101 22,933 471 2.10 743 5.69 0.5138
2019-07-22 2019-06-30 13F IRON MTN INC COM 46284V101 22,462 661 3.03 703 -9.06 0.4723
2019-04-24 2019-03-31 13F IRON MTN INC COM 46284V101 21,801 14,750 209.19 773 215.51 0.5404
2019-02-04 2018-12-31 13F IRON MTN INC COM 46284V101 7,051 7,051 245 0.2083
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.