Who owns IRM?
Institutional ownership of Iron Mountain Incorporated (Delaware) from Form 13F, Q2 2026
1,167 institutional managers reported holding Iron Mountain Incorporated (Delaware) (IRM) in Form 13F filings for Q2 2026, with 257,191,531 shares worth $32.5B. The largest reported holder was BlackRock, Inc. Managers that filed both quarters added a net 3,881,340 shares (+1.5%). 140 opened new positions and 62 sold out.
- Funds holding
- 1,167
- Value held
- $32.5B
- New / sold out
- 140 / 62
- Net shares, same filers
- +1.5%
Holdings as of June 30, 2026, the end of Q2 2026. Managers have 45 days after a quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.
Largest holders of IRM
| Fund | Value | Share of 13F holdings | Shares | Move |
|---|---|---|---|---|
| BlackRock, Inc. | $4.2B | 13.1% | 33,570,910 | Added |
| Vanguard Portfolio Management LLC | $3.2B | 9.9% | 25,568,944 | Added |
| Vanguard Capital Management LLC | $2.4B | 7.4% | 18,953,705 | Added |
| State Street Corp | $2.2B | 6.9% | 17,634,044 | Added |
| Cohen & Steers, Inc. | $1.5B | 4.7% | 12,019,735 | Trimmed |
| Geode Capital Management, LLC | $1.1B | 3.4% | 8,649,249 | Added |
| FMR LLC | $994M | 3.1% | 7,872,365 | Added |
| Dimensional Fund Advisors LP | $584M | 1.8% | 4,625,684 | Added |
| Morgan Stanley | $559M | 1.7% | 4,426,922 | Trimmed |
| Principal Financial Group Inc | $552M | 1.7% | 4,373,424 | Trimmed |
| Charles Schwab Investment Management Inc | $539M | 1.7% | 4,263,487 | Added |
| Northern Trust Corp | $533M | 1.6% | 4,222,967 | Added |
| Norges Bank | $532M | 1.6% | 4,214,697 | New |
| Invesco Ltd. | $514M | 1.6% | 4,065,649 | Added |
| Legal & General Group Plc | $410M | 1.3% | 3,244,741 | Added |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | $403M | 1.2% | 3,193,560 | Added |
| Deutsche Bank Ag\ | $385M | 1.2% | 3,049,079 | Trimmed |
| Goldman Sachs Group Inc | $357M | 1.1% | 2,822,732 | Added |
| Centersquare Investment Management LLC | $294M | 0.9% | 2,323,974 | Added |
| JPMorgan Chase & Co | $288M | 0.9% | 2,212,137 | Added |
| Nuveen, LLC | $280M | 0.9% | 2,218,771 | Added |
| AQR Capital Management LLC | $267M | 0.8% | 2,127,095 | Added |
| Prudential Financial Inc | $249M | 0.8% | 1,974,079 | Trimmed |
| Vontobel Holding Ltd. | $242M | 0.7% | 1,919,656 | Trimmed |
| Daiwa Securities Group Inc. | $235M | 0.7% | 1,861,547 | Trimmed |
Share of 13F holdings is each fund's shares as a share of the 257,191,531 IRM shares all 13F filers reported, not of shares outstanding.
Biggest buyers in Q2 2026
- Norges Bank New+$532M
- UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC Added+$402M
- Goldman Sachs Group Inc Added+$76.6M
- Vanguard Portfolio Management LLC Added+$69.9M
- BlackRock, Inc. Added+$69.4M
- Voloridge Investment Management, LLC New+$52.1M
- FMR LLC Added+$49.0M
- American Century Companies Inc Added+$42.8M
- Aberdeen Group plc Added+$40.5M
- SG Americas Securities, LLC New+$35.9M
Biggest sellers in Q2 2026
- Cohen & Steers, Inc. Trimmed-$524M
- Daiwa Securities Group Inc. Trimmed-$157M
- PGGM Investments Trimmed-$87.8M
- Capital World Investors Trimmed-$82.1M
- Epoch Investment Partners, Inc. Sold out-$63.0M
- Prudential Financial Inc Trimmed-$55.8M
- Jane Street Group, LLC Trimmed-$39.3M
- Bank of America Corp Trimmed-$35.4M
- Sei Investments Co Trimmed-$35.0M
- Point72 Asset Management, L.P. Trimmed-$32.1M
The change in shares since the quarter before, adjusted for stock splits and priced at the Q2 2026 value per share. Funds bought $2.4B and sold $1.9B; 425 added and 372 trimmed.
Schedule 13D and 13G filings on IRM
Owners of more than 5% must file within days, so these can be newer than the 13F data.
- 2025-11-14COHEN & STEERS, INC. SCHEDULE 13G filed by Cohen & Steers IncSchedule 13G
Questions about IRM ownership
- Who owns IRM stock?
- 1,167 institutional investment managers reported IRM positions in their Form 13F filings for Q2 2026, holding 257,191,531 shares worth $32.5B in total. BlackRock, Inc. reported the largest position.
- Are funds buying or selling IRM?
- In Q2 2026, 140 managers opened new IRM positions, 425 added, 372 trimmed and 62 sold out. Managers that filed in both quarters added a net 3,881,340 shares.
- How current is this IRM institutional ownership data?
- It covers holdings as of the end of Q2 2026. Managers have 45 days after the quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.
From the SEC's Form 13F data sets for Q2 2026: every 13F holdings report, matched to IRM by CUSIP. Options are left out. IRM news and filings · IRM insider trades · Top funds