Iron Mountain Incorporated
US ˙ NYSE ˙ US46284V1017

SecurityIRM / Iron Mountain Incorporated
InstitutionMathes Company, Inc.
Latest Disclosed Ownership7,400 shares
Latest Disclosed Value $ 756
Mathes Company, Inc. reports 1.99% decrease in ownership of IRM / Iron Mountain Incorporated

On May 8, 2026 - Mathes Company, Inc. filed a 13F-HR form disclosing ownership of 7,400 shares of Iron Mountain Incorporated (US:IRM) valued at $755,836 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 9, 2026 disclosing 7,550 shares of Iron Mountain Incorporated. The current value of the position is $946,830 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)
2026-05-08 2026-03-31 13F Iron Mountain COM 46284V101 7,400 -150 -1.99 1 0.2762
2026-02-09 2025-12-31 13F Iron Mountain COM 46284V101 7,550 0 0.00 1 0.2233
2025-11-12 2025-09-30 13F IRON MTN INC DEL COM 46284V101 7,550 -500 -6.21 1 0.2764
2025-08-05 2025-06-30 13F Iron Mountain COM 46284V101 8,050 0 0.00 1 0.3064
2025-05-01 2025-03-31 13F IRON MTN INC COM 46284V101 8,050 -100 -1.23 1 0.2818
2025-01-31 2024-12-31 13F Iron Mountain COM 46284V101 8,150 0 0.00 1 0.3124
2024-10-29 2024-09-30 13F Iron Mountain COM 46284V101 8,150 0 0.00 1 0.3415
2024-08-12 2024-06-30 13F Iron Mountain COM 46284V101 8,150 -1,800 -18.09 1 0.2650
2024-05-02 2024-03-31 13F Iron Mountain COM 46284V101 9,950 0 0.00 1 0.2990
2024-01-30 2023-12-31 13F Iron Mountain COM 46284V101 9,950 0 0.00 1 0.2868
2023-10-26 2023-09-30 13F Iron Mountain COM 46284V101 9,950 0 0.00 1 0.2747
2023-07-25 2023-06-30 13F Iron Mountain COM 46284V101 9,950 -2,000 -16.74 1 0.2472
2023-01-25 2022-12-31 13F IRON MTN INC DEL COM 46284V101 11,950 0 0.00 1 -100.00 0.3008
2022-10-18 2022-09-30 13F Iron Mountain COM 46284V101 11,950 -1,900 -13.72 525 -22.11 0.2927
2022-08-01 2022-06-30 13F Iron Mountain COM 46284V101 13,850 0 0.00 674 -12.13 0.3276
2022-06-15 2022-03-31 13F Iron Mountain COM 46284V101 13,850 -23,000 -62.42 767 -60.22 0.2973
2022-02-04 2021-12-31 13F Iron Mountain COM 46284V101 36,850 -2,300 -5.87 1,928 13.35 0.6595
2021-10-29 2021-09-30 13F Iron Mountain COM 46284V101 39,150 39,150 1,701 0.6311
2021-07-20 2021-06-30 13F Iron Mountain COM 46284V101 0 -38,950 -100.00 0 -100.00
2021-04-28 2021-03-31 13F Iron Mountain COM 46284V101 38,950 0 0.00 1,442 25.61 0.5567
2021-01-20 2020-12-31 13F Iron Mountain COM 46284V101 38,950 6,000 18.21 1,148 30.01 0.4661
2020-10-26 2020-09-30 13F Iron Mountain COM 46284V101 32,950 2,950 9.83 883 12.77 0.4114
2020-07-27 2020-06-30 13F Iron Mountain COM 46284V101 30,000 1,250 4.35 783 14.47 0.3895
2020-04-21 2020-03-31 13F Iron Mountain COM 46284V101 28,750 -2,100 -6.81 684 -30.42 0.4548
2020-01-30 2019-12-31 13F Iron Mountain COM 46284V101 30,850 -1,000 -3.14 983 -4.75 0.4590
2019-10-21 2019-09-30 13F Iron Mountain COM 46284V101 31,850 10,050 46.10 1,032 51.32 0.5324
2019-07-29 2019-06-30 13F Iron Mountain COM 46284V101 21,800 21,800 682 0.3611
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.