Iron Mountain Incorporated
US ˙ NYSE ˙ US46284V1017

SecurityIRM / Iron Mountain Incorporated
InstitutionSowell Financial Services LLC
Latest Disclosed Ownership3,263 shares
Latest Disclosed Value $ 333,271
Sowell Financial Services LLC reports 18.91% increase in ownership of IRM / Iron Mountain Incorporated

On April 20, 2026 - Sowell Financial Services LLC filed a 13F-HR form disclosing ownership of 3,263 shares of Iron Mountain Incorporated (US:IRM) valued at $333,283 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 21, 2026 disclosing 2,744 shares of Iron Mountain Incorporated. This represents a change in shares of 18.91% during the quarter. The current value of the position is $417,501 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)
2026-04-20 2026-03-31 13F IRON MTN INC DEL COM 46284V101 3,263 519 18.91 333 46.70 0.0123
2026-01-21 2025-12-31 13F IRON MTN INC DEL COM 46284V101 2,744 -306 -10.03 228 -26.77 0.0084
2025-10-17 2025-09-30 13F IRON MTN INC DEL COM 46284V101 3,050 -168 -5.22 311 -6.06 0.0119
2025-07-14 2025-06-30 13F IRON MTN INC DEL COM 46284V101 3,218 -96 -2.90 330 15.79 0.0134
2025-04-17 2025-03-31 13F IRON MTN INC DEL COM 46284V101 3,314 3,314 285 0.0130
2021-08-05 2021-06-30 13F IRON MTN INC NEW COM REIT 46284V101 0 -1,402 -100.00 0 -100.00
2021-05-07 2021-03-31 13F IRON MTN INC NEW COM REIT 46284V101 1,402 33 2.41 58 45.00 0.0020
2021-01-13 2020-12-31 13F IRON MTN INC NEW COM REIT 46284V101 1,369 250 22.34 40 33.33 0.0017
2020-11-12 2020-09-30 13F IRON MTN INC NEW COM REIT 46284V101 1,119 -339 -23.25 30 -21.05 0.0015
2020-08-13 2020-06-30 13F IRON MTN INC NEW COM REIT 46284V101 1,458 354 32.07 38 46.15 0.0021
2020-05-12 2020-03-31 13F IRON MTN INC NEW COM REIT 46284V101 1,104 -2,210 -66.69 26 -75.47 0.0019
2020-02-07 2019-12-31 13F IRON MTN INC NEW COM REIT 46284V101 3,314 3,118 1,590.82 106 1,666.67 0.0081
2019-11-14 2019-09-30 13F IRON MTN INC NEW COM REIT 46284V101 196 196 6 0.0005
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.