Iron Mountain Incorporated
US ˙ NYSE ˙ US46284V1017

SecurityIRM / Iron Mountain Incorporated
InstitutionCommerce Bank
Latest Disclosed Ownership16,393 shares
Latest Disclosed Value $ 1,674,380
Commerce Bank reports 1.29% increase in ownership of IRM / Iron Mountain Incorporated

On May 11, 2026 - Commerce Bank filed a 13F-HR form disclosing ownership of 16,393 shares of Iron Mountain Incorporated (US:IRM) valued at $1,674,381 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 16,184 shares of Iron Mountain Incorporated. This represents a change in shares of 1.29% during the quarter. The current value of the position is $2,097,484 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)
2026-05-11 2026-03-31 13F IRON MTN INC DEL COM 46284V101 16,393 209 1.29 1,674 24.74 0.0035
2026-02-13 2025-12-31 13F IRON MTN INC DEL COM 46284V101 16,184 -7 -0.04 1,342 -18.67 0.0074
2025-11-12 2025-09-30 13F IRON MTN INC DEL COM 46284V101 16,191 -2,027 -11.13 1,651 -11.67 0.0092
2025-08-07 2025-06-30 13F IRON MTN INC DEL COM 46284V101 18,218 44 0.24 1,869 19.51 0.0110
2025-05-08 2025-03-31 13F IRON MTN INC DEL COM 46284V101 18,174 -1,480 -7.53 1,564 -24.31 0.0100
2025-02-13 2024-12-31 13F IRON MTN INC DEL COM 46284V101 19,654 -122 -0.62 2,066 -12.09 0.0127
2024-11-08 2024-09-30 13F IRON MTN INC DEL COM 46284V101 19,776 -5,773 -22.60 2,350 2.62 0.0144
2024-08-12 2024-06-30 13F IRON MTN INC DEL COM 46284V101 25,549 447 1.78 2,290 13.71 0.0148
2024-05-03 2024-03-31 13F IRON MTN INC DEL COM 46284V101 25,102 2,855 12.83 2,013 29.37 0.0133
2024-02-09 2023-12-31 13F IRON MTN INC DEL COM 46284V101 22,247 450 2.06 1,557 20.15 0.0111
2023-11-14 2023-09-30 13F IRON MTN INC DEL COM 46284V101 21,797 211 0.98 1,296 5.63 0.0102
2023-08-08 2023-06-30 13F IRON MTN INC DEL COM 46284V101 21,586 979 4.75 1,227 12.48 0.0092
2023-05-04 2023-03-31 13F IRON MTN INC DEL COM 46284V101 20,607 993 5.06 1,090 11.57 0.0085
2023-02-10 2022-12-31 13F IRON MTN INC DEL COM 46284V101 19,614 -237,465 -92.37 978 -91.36 0.0079
2022-11-04 2022-09-30 13F IRON MTN INC DEL COM 46284V101 257,079 276 0.11 11,304 -9.59 0.0982
2022-08-12 2022-06-30 13F IRON MTN INC COM 46284V101 256,803 8 0.00 12,503 -12.13 0.1019
2022-05-09 2022-03-31 13F IRON MTN INC COM 46284V101 256,795 2,741 1.08 14,229 7.03 0.0975
2022-02-14 2021-12-31 13F IRON MTN INC COM 46284V101 254,054 833 0.33 13,294 20.83 0.0869
2021-11-09 2021-09-30 13F IRON MTN INC COM 46284V101 253,221 -268,470 -51.46 11,002 -50.17 0.0778
2021-08-09 2021-06-30 13F IRON MTN INC COM 46284V101 521,691 -197 -0.04 22,078 14.30 0.1567
2021-05-05 2021-03-31 13F IRON MTN INC COM 46284V101 521,888 3,151 0.61 19,315 26.31 0.1469
2021-02-09 2020-12-31 13F IRON MTN INC COM 46284V101 518,737 241,534 87.13 15,292 105.90 0.1237
2020-11-06 2020-09-30 13F IRON MTN INC COM 46284V101 277,203 184,737 199.79 7,427 207.66 0.0672
2020-08-07 2020-06-30 13F IRON MTN INC COM 46284V101 92,466 92,466 1,366.55 2,414 954.15 0.0235
2013-11-05 2013-09-30 13F/A-2 IRON MTN COM 462846106 0 -6,305 -100.00 0 -100.00
2013-08-07 2013-06-30 13F IRON MTN COM 462846106 6,305 0 0.00 229 0.00 0.0043
2013-08-08 2013-03-31 13F/A-1 IRON MTN COM 462846106 6,305 6,305 229 0.0045
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.