IRON MOUNTAIN INC (IRM) Institutional Selling Activity
Several institutional investors tracked by InsiderSet reduced exposure to IRON MOUNTAIN INC (IRM) during the quarter ended June 30, 2026 based on sequential SEC Form 13F filings.
The largest disclosed institutional seller of IRM during the latest reporting period reduced its reported position by approximately $8.51M based on quarter-end filing values.
Institutional selling activity may reflect profit-taking, sector rotation, portfolio rebalancing, or changing conviction levels among major investment firms. InsiderSet tracks quarter-over-quarter holding reductions, full exits, estimated value changes, and historical selling activity using publicly disclosed SEC filing data.
The investors covered on this page collectively reduced approximately $9.27M in reported IRM exposure during the latest filing period, although many institutional holders continue to maintain significant long-term ownership positions in IRON MOUNTAIN INC.
| Portfolio quarter | Name | Type | Quantity | Remaining | Reported stock balance |
|---|---|---|---|---|---|
| Q1 2026 | Renaissance Technologies LLC | Sell | -83,363 | 2,400 | $245,136 |
| Q4 2025 | Sequoia Financial Advisors | Sell | -841 | 9,273 | $769,181 |
| Q3 2025 | Sequoia Financial Advisors | Sell | -554 | 10,114 | $1,031,023 |
| Q3 2024 | Sequoia Financial Advisors | Sell | -289 | 7,646 | $908,783 |
| Q1 2024 | Sequoia Financial Advisors | Sell | -3,168 | 7,073 | $567,447 |
| Q4 2022 | Renaissance Technologies LLC | Sell | -53,900 | 80,600 | $4,018 |
| Q3 2022 | Renaissance Technologies LLC | Sell | -143,200 | 134,500 | $5,914 |
| Q1 2022 | Renaissance Technologies LLC | Sell | -241,263 | 116,300 | $6,444 |
| Q3 2021 | Renaissance Technologies LLC | Sell | -199,200 | 173,363 | $7,533 |
| Q1 2020 | Renaissance Technologies LLC | Sell | -1,500 | 88,300 | $2,102 |
| Q4 2019 | Parnassus Endeavor Fund | Sell | -1,270,959 | 5,937,855 | $189,240 |
| Q2 2019 | Parnassus Endeavor Fund | Sell | -2,403,963 | 7,129,889 | $223,165 |
| Q1 2019 | Renaissance Technologies LLC | Sell | -36,900 | 89,800 | $3,184 |
| Q1 2019 | Parnassus Endeavor Fund | Sell | -5,130 | 9,533,852 | $338,071 |
| Q4 2018 | Parnassus Endeavor Fund | Sell | -3,806,456 | 9,538,982 | $309,158 |
| Q4 2018 | Renaissance Technologies LLC | Sell | -55,800 | 126,700 | $4,106 |
| Q4 2017 | Renaissance Technologies LLC | Sell | -283,701 | 54,062 | $2,040 |
| Q3 2016 | Parnassus Endeavor Fund | Sell | -1,042,939 | 10,629,968 | $398,943 |
| Q2 2016 | Parnassus Endeavor Fund | Sell | -351,174 | 11,672,907 | $464,932 |
Frequently asked questions about IRM activity
Which institutional owners are buying IRM?
Institutional owners buying IRM include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.
What does "buy" mean in IRM activity?
"Buy" means an investor increased their reported position in IRM compared to the prior reporting period. This reflects growing exposure to IRON MOUNTAIN INC (IRM) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).
Is institutional interest in IRM increasing?
Institutional interest in IRM can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.