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IRM · Iron Mountain Inc · Holdings

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$113.39 +2.26 (+2.03%) At close · Oct 2
Market Cap
$33.16B
Shares
297.70M
Volume · Oct 2 1.93M Avg daily vol (3M) 1.77M

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Some SEC filings for this period have not finished importing. Holder totals and changes may be incomplete; these filings remain queued for recovery.
The Sep 30, 2026 filing window is still open — showing the latest known positions. Funds that have not filed yet carry their prior-quarter positions; a fund that filed without this stock counts as sold out. Each fund's Change is measured against its own previous reported quarter, shown in the Reported column. Pick a completed quarter in the Quarter selector below to put every fund on one quarter and see the stock-wide activity breakdown.
Holders: 1,182
Total Value: $32,788,668,177
Total Shares: 260,711,676
Showing 1–100 of 1,211 holdings by value · page 1 of 13

Institutional Ownership Trend

27 quarters

Holder Concentration

Across 1,179 13F filers
Top Holder
12.9%
Sep 2023 → Jun 2026 · range 12.9% – 20.1%
of institutional value
Top 5
41.5%
Sep 2023 → Jun 2026 · range 41.5% – 49.2%
of institutional value
Top 10
53.0%
Sep 2023 → Jun 2026 · range 53.0% – 57.5%
of institutional value
HHI
442
Sep 2023 → Jun 2026 · range 442 – 685
Broadly held
Showing 100 of 1,211
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Holder Value (USD) % of 13F Shares Open
Key facts CIK 1020569 CUSIP 46284V101 13F (30d) 33 filings 22 filers Visit website Investor relations