Who owns IRON MOUNTAIN INC?
Prices and market caps: Cboe delayed data, at least 15 minutes delayed. Not real-time. Fundamentals from company filings.
Institutional ownership of IRM from SEC Form 13F filings across 1,165 reporting managers. All positions are from one synchronized reporting period — 2026-06-30 books, filed up to 45 days after quarter end — so every row is comparable.
As of the 2026-06-30 reporting period, 1,165 institutions disclosed 257.0M shares of IRON MOUNTAIN INC worth $32.43B — about 86.3% of shares outstanding; the largest disclosed holder is BlackRock, Inc.. Source: SEC Form 13F filings, parsed by EvidInvest.
1,165
13F holders
$32.43B
value, 2026 filers
86.3%
of shares outstanding (257.0M sh)
171
new positions (2026 filers)
Top institutional holders
ordered by shares owned · positions as of 2026-06-30 · % of fund = share of the manager's own book · % of co. = share of IRM's shares outstanding
| # | Manager | Shares | Value | % of fund | % of co. | Δ shares QoQ |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 33.6M | $4.24B | 0.1% | 11.3% | +1.7% |
| 2 | VANGUARD PORTFOLIO MANAGEMENT LLC | 25.6M | $3.23B | 0.1% | 8.6% | +2.2% |
| 3 | VANGUARD CAPITAL MANAGEMENT LLC | 19.0M | $2.39B | 0.1% | 6.4% | +1.0% |
| 4 | STATE STREET CORP | 17.6M | $2.24B | 0.1% | 5.9% | +0.5% |
| 5 | COHEN & STEERS, INC. | 12.0M | $1.52B | 2.4% | 4% | -25.7% |
| 6 | GEODE CAPITAL MANAGEMENT, LLC | 8.6M | $1.09B | 0.1% | 2.9% | +1.9% |
| 7 | FMR LLC | 7.9M | $994.4M | 0.0% | 2.6% | +5.2% |
| 8 | DIMENSIONAL FUND ADVISORS LP | 4.6M | $584.3M | 0.1% | 1.6% | +1.6% |
| 9 | MORGAN STANLEY | 4.4M | $559.2M | 0.0% | 1.5% | -4.8% |
| 10 | PRINCIPAL FINANCIAL GROUP INC | 4.4M | $552.4M | 0.3% | 1.5% | -4.2% |
| 11 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 4.3M | $538.5M | 0.1% | 1.4% | +6.2% |
| 12 | NORTHERN TRUST CORP | 4.2M | $533.4M | 0.1% | 1.4% | +1.7% |
| 13 | NORGES BANKNEW | 4.2M | $532.4M | 0.1% | 1.4% | new |
| 14 | Invesco Ltd. | 4.1M | $513.5M | 0.0% | 1.4% | +3.7% |
| 15 | Legal & General Group Plc | 3.2M | $409.8M | 0.1% | 1.1% | +3.5% |
| 16 | UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 3.2M | $403.4M | 0.1% | 1.1% | +29674.0% |
| 17 | DEUTSCHE BANK AG\ | 3.0M | $385.1M | 0.1% | 1% | -1.4% |
| 18 | GOLDMAN SACHS GROUP INC | 2.8M | $356.5M | 0.0% | 0.9% | +27.3% |
| 19 | CENTERSQUARE INVESTMENT MANAGEMENT LLC | 2.3M | $293.5M | 2.5% | 0.8% | +0.6% |
| 20 | Nuveen, LLC | 2.2M | $280.3M | 0.1% | 0.7% | +7.3% |
| 21 | JPMORGAN CHASE & CO | 2.2M | $287.5M | 0.0% | 0.7% | +4.2% |
| 22 | AQR CAPITAL MANAGEMENT LLC | 2.1M | $266.5M | 0.1% | 0.7% | +15.2% |
| 23 | PRUDENTIAL FINANCIAL INC | 2.0M | $249.3M | 0.3% | 0.7% | -18.3% |
| 24 | Vontobel Holding Ltd. | 1.9M | $242.5M | 0.8% | 0.6% | -9.3% |
| 25 | Daiwa Securities Group Inc. | 1.9M | $235.1M | 0.5% | 0.6% | -40.1% |
Source: SEC Form 13F-HR filings (institutional managers over $100M in US-listed positions). 13Fs disclose long positions only, up to 45 days after quarter end; each manager's latest filed quarter is shown per row and dollar values are the manager's filed marks. Aggregates labeled "2026 filers" count only managers whose latest book is a 2026 quarter. Related: valuation · options positioning · supply chain. Research, not investment advice.