Iron Mountain Incorporated
DE ˙ DB ˙ US46284V1017
108,60 € ↓ -0,40 (-0,37%)
2026-05-29
DEL PRIS
SecurityDE:I5M / Iron Mountain Incorporated
InstitutionBrown Advisory Inc
Latest Disclosed Ownership21,830 shares
Latest Disclosed Value $ 2,229,716
Brown Advisory Inc reports 36.28% increase in ownership of I5M / Iron Mountain Incorporated

On May 15, 2026 - Brown Advisory Inc filed a 13F-HR form disclosing ownership of 21,830 shares of Iron Mountain Incorporated (DE:I5M) valued at $1,938,067 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 16,019 shares of Iron Mountain Incorporated. This represents a change in shares of 36.28% during the quarter. The current value of the position is $2,370,738 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)
2026-05-15 2026-03-31 13F IRON MTN INC DEL COM 46284V101 21,830 5,811 36.28 2,230 67.85 0.0016
2026-02-13 2025-12-31 13F IRON MTN INC DEL COM 46284V101 16,019 176 1.11 1,329 -17.77 0.0019
2025-11-14 2025-09-30 13F IRON MTN INC DEL COM 46284V101 15,843 2,958 22.96 1,615 22.26 0.0021
2025-08-13 2025-06-30 13F IRON MTN INC DEL COM 46284V101 12,885 331 2.64 1,322 22.31 0.0017
2025-04-30 2025-03-31 13F IRON MTN INC DEL COM 46284V101 12,554 -7,443 -37.22 1,080 -48.60 0.0015
2025-02-14 2024-12-31 13F IRON MTN INC DEL COM 46284V101 19,997 7,436 59.20 2,102 40.82 0.0027
2024-11-13 2024-09-30 13F IRON MTN INC DEL COM 46284V101 12,561 1,590 14.49 1,493 51.78 0.0019
2024-08-14 2024-06-30 13F IRON MTN INC DEL COM 46284V101 10,971 739 7.22 983 19.88 0.0013
2024-04-24 2024-03-31 13F IRON MTN INC DEL COM 46284V101 10,232 138 1.37 821 16.15 0.0011
2024-02-08 2023-12-31 13F IRON MTN INC DEL COM 46284V101 10,094 224 2.27 706 20.48 0.0010
2023-10-25 2023-09-30 13F IRON MTN INC DEL COM 46284V101 9,870 2,005 25.49 587 31.39 0.0010
2023-07-31 2023-06-30 13F IRON MTN INC DEL COM 46284V101 7,865 -158 -1.97 447 5.19 0.0007
2023-05-08 2023-03-31 13F IRON MTN INC DEL COM 46284V101 8,023 148 1.88 424 8.16 0.0007
2023-02-13 2022-12-31 13F IRON MTN INC DEL COM 46284V101 7,875 1,043 15.27 393 30.23 0.0007
2022-11-14 2022-09-30 13F IRON MTN INC DEL COM 46284V101 6,832 315 4.83 301 -5.05 0.0006
2022-11-14 2022-06-30 13F/A-2 IRON MTN INC COM 46284V101 6,517 500 8.31 317 -4.80 0.0006
2022-09-13 2022-06-30 13F/A-1 IRON MTN INC COM 46284V101 15,205 -11 740 0.0013
2022-11-14 2022-03-31 13F/A-2 IRON MTN INC COM 46284V101 6,017 2,000 49.79 333 58.57 0.0005
2022-09-13 2022-03-31 13F/A-1 IRON MTN INC COM 46284V101 15,216 11,199 843 0.0012
2022-01-27 2021-12-31 13F IRON MTN INC COM 46284V101 4,017 4,017 210 0.0003
2019-05-15 2019-03-31 13F IRON MTN INC COM 46284V101 0 -45,958 -100.00 0 -100.00
2019-02-13 2018-12-31 13F IRON MTN INC COM 46284V101 45,958 -926 -1.98 1,489 -8.03 0.0050
2018-11-13 2018-09-30 13F IRON MTN INC COM 46284V101 46,884 1,183 2.59 1,619 1.19 0.0046
2018-08-10 2018-06-30 13F IRON MTN INC COM 46284V101 45,701 45,701 1,600 0.0049
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.