Iron Mountain Incorporated
US ˙ NYSE ˙ US46284V1017

SecurityIRM / Iron Mountain Incorporated
InstitutionKBC Group NV
Latest Disclosed Ownership80,345 shares
Latest Disclosed Value $ 8,206
KBC Group NV reports 48.00% decrease in ownership of IRM / Iron Mountain Incorporated

On May 7, 2026 - KBC Group NV filed a 13F-HR form disclosing ownership of 80,345 shares of Iron Mountain Incorporated (US:IRM) valued at $8,206,438 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 154,509 shares of Iron Mountain Incorporated. This represents a change in shares of -48.00% during the quarter. The current value of the position is $10,280,143 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)
2026-05-07 2026-03-31 13F IRON MTN INC DEL COM 46284V101 80,345 -74,164 -48.00 8 -33.33 0.0106
2026-01-26 2025-12-31 13F IRON MTN INC DEL COM 46284V101 154,509 -137,969 -47.17 13 -58.62 0.0292
2026-01-20 2025-09-30 13F IRON MTN INC DEL COM 46284V101 292,478 226,790 345.25 30 383.33 0.0715
2025-08-08 2025-06-30 13F IRON MTN INC DEL COM 46284V101 65,688 -1,665 -2.47 7 20.00 0.0182
2025-04-25 2025-03-31 13F IRON MTN INC DEL COM 46284V101 67,353 -334,908 -83.26 6 -88.10 0.0180
2025-01-22 2024-12-31 13F IRON MTN INC DEL COM 46284V101 402,261 96,869 31.72 42 16.67 0.1165
2024-11-06 2024-09-30 13F IRON MTN INC DEL COM 46284V101 305,392 240,195 368.41 36 620.00 0.1096
2024-07-17 2024-06-30 13F IRON MTN INC DEL COM 46284V101 65,197 -5,235 -7.43 6 0.00 0.0177
2024-05-08 2024-03-31 13F IRON MTN INC DEL COM 46284V101 70,432 20,311 40.52 6 66.67 0.0179
2024-02-13 2023-12-31 13F IRON MTN INC DEL COM 46284V101 50,121 -3,454 -6.45 4 0.00 0.0124
2024-02-15 2023-09-30 13F/A-1 IRON MTN INC DEL COM 46284V101 53,575 34,367 178.92 3 200.00 0.0130
2023-11-22 2023-09-30 13F IRON MTN INC DEL COM 46284V101 18,874 0 1 0.0045
2024-02-15 2023-06-30 13F/A-1 IRON MTN INC DEL COM 46284V101 19,208 0 0.00 1 0.00 0.0045
2023-07-28 2023-06-30 13F IRON MTN INC DEL COM 46284V101 18,874 18,874 1 0.0045
2024-02-14 2023-03-31 13F/A-1 IRON MTN INC DEL COM 46284V101 19,208 6,125 46.82 1 0.0043
2024-02-14 2022-12-31 13F/A-1 IRON MTN INC DEL COM 46284V101 13,083 10 0.08 1 0.0032
2023-02-13 2022-12-31 13F IRON MTN INC DEL COM 46284V101 12,749 -324 1 0.0000
2024-02-15 2022-09-30 13F/A-1 IRON MTN INC DEL COM 46284V101 13,073 324 2.54 1 0.0030
2022-11-08 2022-09-30 13F IRON MTN INC DEL COM 46284V101 12,749 0 561 0.0029
2024-02-14 2022-06-30 13F/A-1 IRON MTN INC COM 46284V101 12,749 0 0.00 1 -100.00 0.0031
2022-07-26 2022-06-30 13F IRON MTN INC COM 46284V101 12,749 0 621 0.0031
2024-02-14 2022-03-31 13F/A-1 IRON MTN INC COM 46284V101 12,749 0 0.00 1 0.0028
2022-05-06 2022-03-31 13F IRON MTN INC COM 46284V101 12,749 0 706 0.0026
2024-02-14 2021-12-31 13F/A-1 IRON MTN INC COM 46284V101 12,749 -42,960 -77.12 1 -100.00 0.0022
2022-02-03 2021-12-31 13F IRON MTN INC COM 46284V101 12,749 -42,960 667 0.0021
2021-11-10 2021-09-30 13F IRON MTN INC COM 46284V101 55,709 20,037 56.17 2,421 60.33 0.0089
2022-02-15 2021-06-30 13F/A-1 IRON MTN INC COM 46284V101 35,672 -47,350 -57.03 1,510 -50.86 0.0054
2021-08-11 2021-06-30 13F IRON MTN INC COM 46284V101 35,672 -47,350 1,510 0.0054
2022-02-14 2021-03-31 13F/A-1 IRON MTN INC COM 46284V101 83,022 -26,359 -24.10 3,073 -90.47 0.0124
2021-04-26 2021-03-31 13F IRON MOUNTAIN COM 46284V101 83,022 -26,359 3,073 0.0124
2022-02-14 2020-12-31 13F/A-1 IRON MTN INC COM 46284V101 109,381 -9,764 -8.20 32,246 910.21 0.0152
2021-02-10 2020-12-31 13F IRON MTN INC COM 46284V101 109,381 -9,764 3,225 0.0148
2022-02-14 2020-09-30 13F/A-1 IRON MTN INC COM 46284V101 119,145 88,065 283.35 3,192 293.59 0.0188
2020-10-28 2020-09-30 13F IRON MTN INC COM 46284V101 119,145 88,065 3,192 0.0189
2022-02-14 2020-06-30 13F/A-1 IRON MTN INC COM 46284V101 31,080 -5,953 -16.07 811 -7.95 0.0054
2020-08-10 2020-06-30 13F IRON MTN INC COM 46284V101 31,080 -5,953 811 0.0054
2020-05-04 2020-03-31 13F IRON MTN INC COM 46284V101 37,033 13,592 57.98 881 17.94 0.0074
2020-02-11 2019-12-31 13F IRON MTN INC COM 46284V101 23,441 0 0.00 747 -1.58 0.0047
2019-11-07 2019-09-30 13F IRON MTN INC COM 46284V101 23,441 -223,316 -90.50 759 -90.17 0.0056
2019-08-08 2019-06-30 13F/A-1 IRON MTN INC COM 46284V101 246,757 19,608 8.63 7,723 -4.12 0.0598
2019-07-30 2019-06-30 13F IRON MTN INC COM 46284V101 246,757 -201,779 7,723
2019-08-07 2019-03-31 13F/A-1 IRON MTN INC COM 46284V101 227,149 139,308 158.59 8,055 182.93 0.0664
2019-05-10 2019-03-31 13F IRON MTN INC COM 46284V101 227,149 139,308 8,055
2019-01-31 2018-12-31 13F IRON MTN INC COM 46284V101 87,841 0 0.00 2,847 -6.10 0.0317
2018-11-14 2018-09-30 13F IRON MTN INC COM 46284V101 87,841 62,471 246.24 3,032 241.44 0.0229
2018-08-03 2018-06-30 13F IRON MTN INC COM 46284V101 25,370 -2,090 -7.61 888 -1.55 0.0077
2018-08-03 2018-03-31 13F/A-1 IRON MTN INC COM 46284V101 27,460 0 0.00 902 -12.93 0.0083
2018-05-09 2018-03-31 13F IRON MTN INC COM 46284V101 27,460 0 902
2018-08-03 2017-12-31 13F/A-1 IRON MTN INC COM 46284V101 27,460 -6,135 -18.26 1,036 -20.73 0.0089
2018-02-07 2017-12-31 13F IRON MTN INC COM 46284V101 27,460 -6,135 1,036
2017-11-13 2017-09-30 13F IRON MTN INC COM 46284V101 33,595 -11,741 -25.90 1,307 -16.06 0.0119
2017-08-04 2017-06-30 13F IRON MTN INC COM 46284V101 45,336 -56,570 -55.51 1,557 -57.17 0.0150
2017-05-10 2017-03-31 13F IRON MTN INC COM 46284V101 101,906 24,354 31.40 3,635 44.30 0.0328
2017-02-16 2016-12-31 13F IRON MTN INC COM 46284V101 77,552 22,615 41.17 2,519 22.16 0.0250
2016-11-03 2016-09-30 13F IRON MTN INC COM 46284V101 54,937 25,651 87.59 2,062 76.84 0.0244
2016-08-03 2016-06-30 13F IRON MTN INC COM 46284V101 29,286 2,837 10.73 1,166 29.99 0.0167
2016-05-11 2016-03-31 13F IRON MTN INC COM 46284V101 26,449 7,641 40.63 897 76.57 0.0149
2016-02-11 2015-12-31 13F IRON MTN INC COM 46284V101 18,808 6,800 56.63 508 36.56 0.0094
2015-11-12 2015-09-30 13F IRON MTN INC COM 46284V101 12,008 2,961 32.73 372 32.86 0.0075
2015-12-16 2015-06-30 13F/A-1 IRON MTN INC COM 46284V101 9,047 0 0.00 280 -15.15 0.0036
2015-07-31 2015-06-30 13F IRON MTN INC COM 46284V101 9,047 280
2015-12-16 2015-03-31 13F/A-1 IRON MTN INC COM 46284V101 9,047 0 0.00 330 -5.71 0.0042
2015-04-30 2015-03-31 13F IRON MTN INC COM 46284V101 9,047 330
2015-12-15 2014-12-31 13F/A-1 IRON MTN COM 462846106 9,047 2,941 48.17 350 75.88 0.0042
2015-02-12 2014-12-31 13F IRON MTN COM 462846106 9,047 350
2014-10-16 2014-09-30 13F IRON MTN COM 462846106 6,106 -3,542 -36.71 199 -41.81 0.0069
2014-08-01 2014-06-30 13F IRON MTN COM 462846106 9,648 0 0.00 342 28.57 0.0039
2014-04-30 2014-03-31 13F IRON MTN COM 462846106 9,648 -8,409 -46.57 266 -51.46 0.0042
2014-01-21 2013-12-31 13F IRON MOUNTAIN COM 462846106 18,057 8,370 86.40 548 109.16 0.0083
2013-11-06 2013-09-30 13F IRON MOUNTAIN COM 462846106 9,687 0 0.00 262 1.55 0.0042
2013-07-29 2013-06-30 13F IRON MOUNTAIN COM 462846106 9,687 9,687 258 0.0048
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.