Iron Mountain Incorporated
MX ˙ BMV ˙ US46284V1017
SecurityMX:IRM1 / Iron Mountain Incorporated
InstitutionTwo Sigma Advisers, Lp
Latest Disclosed Ownership130,324 shares
Latest Disclosed Value $ 10,810,376
Two Sigma Advisers, Lp ownership in IRM1 / Iron Mountain Incorporated

On February 17, 2026 - Two Sigma Advisers, Lp filed a 13F-HR form disclosing ownership of 130,324 shares of Iron Mountain Incorporated (MX:IRM1) valued at $10,810,376 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 14, 2025 disclosing 6,500 shares of Iron Mountain Incorporated. This represents a change in shares of 1,904.98% during the quarter.

Two Sigma Advisers, Lp has a history of taking positions in derivatives of the underlying security (IRM1) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD and put options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:IRM1 / Iron Mountain Incorporated Historical Put/Call Ratio
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)
2026-02-17 2025-12-31 13F IRON MTN INC DEL COM 46284V101 130,324 123,824 1,904.98 10,810 1,532.93 0.0210
2025-11-14 2025-09-30 13F IRON MTN INC DEL COM 46284V101 6,500 -29,600 -81.99 663 -82.12 0.0013
2025-08-14 2025-06-30 13F IRON MTN INC DEL COM 46284V101 36,100 -26,600 -42.42 3,703 -31.37 0.0076
2025-05-15 2025-03-31 13F IRON MTN INC DEL COM 46284V101 62,700 55,000 714.29 5,395 566.75 0.0121
2025-02-14 2024-12-31 13F IRON MTN INC DEL COM 46284V101 7,700 7,700 809 0.0019
2022-02-14 2021-12-31 13F IRON MTN INC COM 46284V101 0 -36,100 -100.00 0 -100.00
2021-11-15 2021-09-30 13F IRON MTN INC COM 46284V101 36,100 -18,800 -34.24 1,569 -32.46 0.0041
2021-08-16 2021-06-30 13F IRON MTN INC COM 46284V101 54,900 -28,300 -34.01 2,323 -24.55 0.0061
2021-05-17 2021-03-31 13F IRON MTN INC COM 46284V101 83,200 -9,300 -10.05 3,079 12.91 0.0085
2021-02-16 2020-12-31 13F IRON MTN INC COM 46284V101 92,500 -311,300 -77.09 2,727 -74.79 0.0073
2020-11-16 2020-09-30 13F IRON MTN INC COM 46284V101 403,800 58,500 16.94 10,818 20.04 0.0309
2020-09-15 2020-06-30 13F/A-1 IRON MTN INC COM 46284V101 345,300 -190,724 -35.58 9,012 -29.36 0.0265
2020-08-14 2020-06-30 13F IRON MTN INC COM 46284V101 345,300 -190,724 9,012 26,041.6870
2020-05-15 2020-03-31 13F IRON MTN INC COM 46284V101 536,024 141,324 35.81 12,757 1.42 0.0488
2020-02-14 2019-12-31 13F IRON MTN INC COM 46284V101 394,700 -41,300 -9.47 12,579 -10.93 0.0292
2019-11-14 2019-09-30 13F IRON MTN INC COM 46284V101 436,000 -46,100 -9.56 14,122 -6.41 0.0346
2019-08-14 2019-06-30 13F IRON MTN INC COM 46284V101 482,100 -60,600 -11.17 15,090 -21.59 0.0376
2019-05-15 2019-03-31 13F IRON MTN INC COM 46284V101 542,700 420,300 343.38 19,244 385.10 0.0485
2019-02-14 2018-12-31 13F IRON MTN INC COM 46284V101 122,400 98,653 415.43 3,967 383.78 0.0108
2018-11-14 2018-09-30 13F IRON MTN INC COM 46284V101 23,747 23,747 820 0.0020
2018-08-14 2018-06-30 13F IRON MTN INC COM 46284V101 0 -144,147 -100.00 0 -100.00
2018-05-15 2018-03-31 13F IRON MTN INC COM 46284V101 144,147 7,900 5.80 4,737 -7.86 0.0128
2018-02-14 2017-12-31 13F IRON MTN INC COM 46284V101 136,247 11,400 9.13 5,141 5.85 0.0139
2017-11-14 2017-09-30 13F IRON MTN INC COM 46284V101 124,847 98,100 366.77 4,857 428.51 0.0138
2017-08-14 2017-06-30 13F IRON MTN INC COM 46284V101 26,747 15,676 141.60 919 132.66 0.0030
2017-05-15 2017-03-31 13F IRON MTN INC COM 46284V101 11,071 -40,112 -78.37 395 -76.23 0.0013
2017-02-14 2016-12-31 13F IRON MTN INC COM 46284V101 51,183 -76 -0.15 1,662 -13.62 0.0064
2016-11-14 2016-09-30 13F IRON MTN INC COM 46284V101 51,259 -108,924 -68.00 1,924 -69.84 0.0082
2016-08-15 2016-06-30 13F IRON MTN INC COM 46284V101 160,183 82,000 104.88 6,380 140.66 0.0324
2016-05-16 2016-03-31 13F IRON MTN INC COM 46284V101 78,183 -80,261 -50.66 2,651 -38.06 0.0148
2016-02-16 2015-12-31 13F IRON MTN INC COM 46284V101 158,444 137,334 650.56 4,280 553.44 0.0255
2015-11-16 2015-09-30 13F IRON MTN INC COM 46284V101 21,110 -25,104 -54.32 655 -53.28 0.0041
2014-02-14 2013-12-31 13F IRON MTN COM 462846106 46,214 10,900 30.87 1,402 46.96 0.0135
2013-11-14 2013-09-30 13F IRON MTN COM 462846106 35,314 -112,224 -76.06 954 -75.71 0.0114
2013-08-14 2013-06-30 13F IRON MTN COM 462846106 147,538 147,538 3,927 0.0561
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2013-11-14 2013-09-30 13F IRON MTN COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2013-08-14 2013-06-30 13F IRON MTN COM Call 45,700 1,216 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2013-11-14 2013-09-30 13F IRON MTN COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2013-08-14 2013-06-30 13F IRON MTN COM Put 24,000 639 n/a n/a n/a
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.