Iron Mountain Incorporated
US ˙ NYSE ˙ US46284V1017

SecurityIRM / Iron Mountain Incorporated
InstitutionOak Thistle LLC
Latest Disclosed Ownership53,641 shares
Latest Disclosed Value $ 5,478,891
Oak Thistle LLC ownership in IRM / Iron Mountain Incorporated

On April 10, 2026 - Oak Thistle LLC filed a 13F-HR form disclosing ownership of 53,641 shares of Iron Mountain Incorporated (US:IRM) valued at $5,478,892 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 21, 2026 disclosing 0 shares of Iron Mountain Incorporated. The current value of the position is $6,863,366 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)
2026-04-10 2026-03-31 13F IRON MTN INC DEL COM 46284V101 53,641 53,641 5,479 0.5319
2026-01-21 2025-12-31 13F IRON MTN INC DEL COM 46284V101 0 -11,980 -100.00 0 -100.00
2025-10-07 2025-09-30 13F IRON MTN INC DEL COM 46284V101 11,980 5,513 85.25 1,221 84.16 0.1862
2025-08-08 2025-06-30 13F IRON MTN INC DEL COM 46284V101 6,467 -14,419 -69.04 663 -63.11 0.0977
2025-05-06 2025-03-31 13F IRON MTN INC DEL COM 46284V101 20,886 13,665 189.24 1,797 137.07 0.3618
2025-01-14 2024-12-31 13F IRON MTN INC DEL COM 46284V101 7,221 3,800 111.08 759 86.70 0.2254
2024-11-12 2024-09-30 13F IRON MTN INC DEL COM 46284V101 3,421 3,421 407 0.1322
2024-08-06 2024-06-30 13F IRON MTN INC DEL COM 46284V101 0 -3,039 -100.00 0 -100.00
2024-04-18 2024-03-31 13F IRON MTN INC DEL COM 46284V101 3,039 3,039 244 0.2188
2024-01-22 2023-12-31 13F IRON MTN INC DEL COM 46284V101 0 -9,462 -100.00 0 -100.00
2023-10-18 2023-09-30 13F IRON MTN INC DEL COM 46284V101 9,462 9,462 563 0.1662
2022-08-01 2022-06-30 13F IRON MTN INC COM 46284V101 0 -11,042 -100.00 0 -100.00
2022-05-10 2022-03-31 13F IRON MTN INC COM 46284V101 11,042 11,042 612 0.2111
2022-05-10 2022-03-31 13F IRON MTN INC COM 46284V101 6,752 374
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.