Iron Mountain IRM Institutional Ownership

NYSE IRM

$111.96 -2.63 (-2.29%)

As of: Nov 13, 2026 · 11:07 AM EST

Institutions by Trading Activity

1,164 Institutions

Increased 601 51.6%

Unchanged 186 16.0%

Reduced 377 32.4%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

86.18%

▲+1.56 pp QoQ

Shares Held by Institutions

256.60Mn

of 297.74Mn outstanding

▲+1.93% QoQ

Shares Outstanding

297.74Mn

41.14Mn held outside 13F filers

Institutional Investors

1,164

filed 13F for Jun 2026

▲+82 vs prior quarter

Net Shares Added (QoQ)

+4.85Mn

accumulated since last quarter

Value of Holdings

$29.40Bn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Nov 4, 2026

Iron Mountain Inc (NYSE:IRM) counted 1,164 institutional investors among its 13F-reported shareholders for the quarter ended June 30, 2026.

These investors held 86.18% of Iron Mountain's outstanding shares at the end of Q2 2026, up from 84.63% in Q1 2026.
Total holdings of Iron Mountain shares rose 1.93% from Q1 2026, and the number of holders rose 12.14% from Q2 2025.
Of these 1,164 holders, 601 added to their positions, 377 reduced their stakes and 186 left their positions unchanged.
Combined, institutional investors held 256.6Mn shares of IRM as of Q2 2026, up 4.85Mn from the prior quarter and up 11.8Mn from a year earlier.
BlackRock, Inc. was the top holder of Iron Mountain as of June 30, 2026, with 33.57Mn shares, or 11.28% of shares outstanding.
Among holders that already owned Iron Mountain, the biggest buyers in Q2 2026 were UBS Asset Management Americas (+3.18Mn shares), Goldman Sachs Group Inc (+606.06K shares), Vanguard Portfolio Management LLC (+553.39K shares), BlackRock, Inc. (+549.56K shares) and FMR LLC (+387.97K shares).
On the other side, among holders that kept a position in Iron Mountain, the largest reductions in Q2 2026 came from Cohen & Steers, Inc. (-4.15Mn shares), Daiwa Securities Group Inc. (-1.25Mn shares), PGGM Investments (-694.9K shares), Capital World Investors (-650K shares) and Prudential Financial Inc (-441.98K shares).
Per Business Quant, the top 10 investors in IRM for the quarter ended June 30, 2026 were BlackRock, Inc. (33.57Mn shares), Vanguard Portfolio Management LLC (25.57Mn shares), Vanguard Capital Management LLC (18.95Mn shares), State Street Corp (17.63Mn shares), Cohen & Steers, Inc. (12.02Mn shares), Geode Capital Management, LLC (8.65Mn shares), FMR LLC (7.87Mn shares), Dimensional Fund Advisors LP (4.63Mn shares), Morgan Stanley (4.43Mn shares) and Principal Financial Group Inc (4.37Mn shares).

Form 13F Holdings

1,164 Institutional Holders

Report period 30 Jun, 2026

Total shares held 256.60Mn

Of outstanding 86.18%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	BlackRock, Inc.	0002012383	33,570,910	11.28%	▲549,556	+1.66%	$4.24Bn
2	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	25,568,944	8.59%	▲553,387	+2.21%	$3.23Bn
3	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	18,953,705	6.37%	▲194,816	+1.04%	$2.39Bn
4	State Street Corp	0000093751	17,634,044	5.92%	▲82,411	+0.47%	$2.24Bn
5	Cohen & Steers, Inc.	0001284812	12,019,735	4.04%	▼4,149,606	-25.66%	$1.52Mn
6	GEODE CAPITAL MANAGEMENT, LLC	0001214717	8,649,249	2.90%	▲163,122	+1.92%	$1.09Bn
7	FMR LLC	0000315066	7,872,365	2.64%	▲387,967	+5.18%	$994.36Mn
8	DIMENSIONAL FUND ADVISORS LP	0000354204	4,625,684	1.55%	▲73,398	+1.61%	$584.31Mn
9	Morgan Stanley	0000895421	4,426,922	1.49%	▼225,325	-4.84%	$559.16Mn
10	Principal Financial Group Inc	0001126328	4,373,424	1.47%	▼192,669	-4.22%	$552.40Mn
11	CHARLES SCHWAB INVESTMENT MANAGEMENT INC	0000884546	4,263,487	1.43%	▲250,480	+6.24%	$538.52Mn
12	Northern Trust Corp	0000073124	4,222,967	1.42%	▲72,481	+1.75%	$533.40Mn
13	NORGES BANK	0001374170	4,214,697	1.42%	▲4,214,697	0.00%	$532.36Mn
14	Invesco Ltd.	0000914208	4,065,649	1.37%	▲144,128	+3.68%	$513.53Mn
15	Legal & General Group Plc	0000764068	3,244,741	1.09%	▲109,667	+3.50%	$409.84Mn
16	UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC	0000861177	3,193,560	1.07%	▲3,182,834	+29,674.01%	$403.38Mn
17	DEUTSCHE BANK AG\	0000948046	3,049,079	1.02%	▼43,005	-1.39%	$385.13Mn
18	Goldman Sachs Group Inc	0000886982	2,822,732	0.95%	▲606,060	+27.34%	$356.54Mn
19	CENTERSQUARE INVESTMENT MANAGEMENT LLC	0001725296	2,323,974	0.78%	▲13,929	+0.60%	$293.54Mn
20	Nuveen, LLC	0001871926	2,218,771	0.75%	▲150,363	+7.27%	$280.25Mn

Showing 1 to 20 of 1,164 holders