Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionRafferty Asset Management, LLC
Latest Disclosed Ownership29,108 shares
Latest Disclosed Value $ 2,973,091
Rafferty Asset Management, LLC reports 23.84% decrease in ownership of IRM1 / Iron Mountain Incorporated

On May 15, 2026 - Rafferty Asset Management, LLC filed a 13F-HR form disclosing ownership of 29,108 shares of Iron Mountain Incorporated (MX:IRM1) valued at $2,973,091 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 38,219 shares of Iron Mountain Incorporated. This represents a change in shares of -23.84% during the quarter.

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 29,108 -9,111 -23.84 2,973 -6.21 0.0121
2026-02-13 2025-12-31 13F IRON MTN INC DEL COM 46284V101 38,219 -1,495 -3.76 3,170 -21.69 0.0110
2025-11-12 2025-09-30 13F IRON MTN INC DEL COM 46284V101 39,714 2,324 6.22 4,048 5.55 0.0131
2025-08-14 2025-06-30 13F IRON MTN INC DEL COM 46284V101 37,390 5,361 16.74 3,835 39.20 0.0127
2025-05-14 2025-03-31 13F IRON MTN INC DEL COM 46284V101 32,029 -6,579 -17.04 2,756 -32.11 0.0117
2025-02-14 2024-12-31 13F IRON MTN INC DEL COM 46284V101 38,608 -3,087 -7.40 4,058 -18.09 0.0144
2024-11-13 2024-09-30 13F IRON MTN INC DEL COM 46284V101 41,695 1,226 3.03 4,955 36.62 0.0170
2024-08-13 2024-06-30 13F IRON MTN INC DEL COM 46284V101 40,469 5,508 15.75 3,627 29.32 0.0135
2024-05-13 2024-03-31 13F IRON MTN INC DEL COM 46284V101 34,961 -4,207 -10.74 2,804 2.34 0.0105
2024-02-13 2023-12-31 13F IRON MTN INC DEL COM 46284V101 39,168 6,561 20.12 2,741 41.38 0.0116
2023-11-13 2023-09-30 13F IRON MTN INC DEL COM 46284V101 32,607 1,568 5.05 1,938 9.93 0.0114
2023-08-11 2023-06-30 13F IRON MTN INC DEL COM 46284V101 31,039 485 1.59 1,764 9.10 0.0099
2023-05-11 2023-03-31 13F IRON MTN INC DEL COM 46284V101 30,554 4,029 15.19 1,617 22.24 0.0110
2023-02-13 2022-12-31 13F IRON MTN INC DEL COM 46284V101 26,525 9,263 53.66 1,322 74.18 0.0111
2022-11-14 2022-09-30 13F IRON MTN INC DEL COM 46284V101 17,262 3,774 27.98 759 15.53 0.0081
2022-08-12 2022-06-30 13F IRON MTN INC COM 46284V101 13,488 -2,340 -14.78 657 -25.09 0.0060
2022-05-13 2022-03-31 13F IRON MTN INC COM 46284V101 15,828 288 1.85 877 7.87 0.0052
2022-02-10 2021-12-31 13F IRON MTN INC COM 46284V101 15,540 -3,114 -16.69 813 0.25 0.0043
2021-11-10 2021-09-30 13F IRON MTN INC COM 46284V101 18,654 -4,425 -19.17 811 -16.99 0.0055
2021-08-10 2021-06-30 13F IRON MTN INC COM 46284V101 23,079 7,909 52.14 977 74.15 0.0062
2021-05-10 2021-03-31 13F IRON MTN INC COM 46284V101 15,170 4,820 46.57 561 83.93 0.0038
2021-02-10 2020-12-31 13F IRON MTN INC COM 46284V101 10,350 -154 -1.47 305 8.54 0.0030
2020-11-13 2020-09-30 13F IRON MTN INC COM 46284V101 10,504 -58,636 -84.81 281 -84.43 0.0034
2020-08-07 2020-06-30 13F IRON MTN INC COM 46284V101 69,140 56,231 435.60 1,805 487.95 0.0254
2020-05-15 2020-03-31 13F IRON MTN INC COM 46284V101 12,909 -41,930 -76.46 307 -82.44 0.0129
2020-02-10 2019-12-31 13F IRON MTN INC COM 46284V101 54,839 4,462 8.86 1,748 7.11 0.0269
2019-11-14 2019-09-30 13F IRON MTN INC COM 46284V101 50,377 -7,652 -13.19 1,632 -10.13 0.0255
2019-08-09 2019-06-30 13F IRON MTN INC COM 46284V101 58,029 -7,465 -11.40 1,816 -21.79 0.0319
2019-05-15 2019-03-31 13F IRON MTN INC COM 46284V101 65,494 9,718 17.42 2,322 28.43 0.0374
2019-02-11 2018-12-31 13F IRON MTN INC COM 46284V101 55,776 -21,353 -27.68 1,808 -32.08 0.0394
2018-11-09 2018-09-30 13F IRON MTN INC COM 46284V101 77,129 -7,964 -9.36 2,662 -10.64 0.0412
2018-08-14 2018-06-30 13F IRON MTN INC COM 46284V101 85,093 13,211 18.38 2,979 26.12 0.0445
2018-05-15 2018-03-31 13F IRON MTN INC COM 46284V101 71,882 11,430 18.91 2,362 3.55 0.0350
2018-02-14 2017-12-31 13F IRON MTN INC COM 46284V101 60,452 16,622 37.92 2,281 33.78 0.0394
2017-11-13 2017-09-30 13F IRON MTN INC COM 46284V101 43,830 4,910 12.62 1,705 27.52 0.0382
2017-08-11 2017-06-30 13F IRON MTN INC COM 46284V101 38,920 -8,287 -17.55 1,337 -20.61 0.0384
2017-05-11 2017-03-31 13F IRON MTN INC COM 46284V101 47,207 34,111 260.47 1,684 296.24 0.0371
2017-02-13 2016-12-31 13F IRON MTN INC COM 46284V101 13,096 -3,632 -21.71 425 -32.32 0.0195
2016-11-14 2016-09-30 13F IRON MTN INC COM 46284V101 16,728 -11,332 -40.38 628 -43.83 0.0229
2016-08-09 2016-06-30 13F IRON MTN INC COM 46284V101 28,060 279 1.00 1,118 18.68 0.0756
2016-05-12 2016-03-31 13F IRON MTN INC COM 46284V101 27,781 9,161 49.20 942 83.27 0.0512
2016-02-12 2015-12-31 13F IRON MTN INC COM 46284V101 18,620 -1,410 -7.04 514 -17.23 0.0618
2015-11-12 2015-09-30 13F IRON MTN INC COM 46284V101 20,030 10,239 104.58 621 104.28 0.0490
2015-08-12 2015-06-30 13F IRON MTN INC COM 46284V101 9,791 -833 -7.84 304 -21.65 0.0204
2015-05-14 2015-03-31 13F IRON MTN INC COM 46284V101 10,624 10,624 388 0.0292
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.