Iron Mountain IRM Institutional Ownership

NYSE IRM

$113.43 +2.19 (+1.97%)

At close: Oct 2, 2026 · 4:00 PM EDT

Institutions by Trading Activity

1,161 Institutions

Increased 597 51.4%

Unchanged 186 16.0%

Reduced 378 32.6%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

87.64%

▲+2.83 pp QoQ

Shares Held by Institutions

260.94Mn

of 297.74Mn outstanding

▲+4.54% QoQ

Shares Outstanding

297.74Mn

36.80Mn held outside 13F filers

Institutional Investors

1,161

filed 13F for Jun 2026

▲+82 vs prior quarter

Net Shares Added (QoQ)

+11.33Mn

accumulated since last quarter

Value of Holdings

$29.60Bn

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

Quarter ending 30 Jun, 2026

Iron Mountain Inc (NYSE:IRM) appears in 3 institutional 13F filings for the quarter ending September 2026.

Collectively, these holders controlled 0.0% of Iron Mountain's outstanding shares in September 2026, down from 87.6% in June 2026.
They increased total shares held in Iron Mountain by 32.0% from the prior quarter, while the number of investors in IRM decreased 99.7% year over year.
Of these 3 funds, 2 grew their exposure to Iron Mountain, 1 cut back, and 0 maintained positions.
In total, institutional investors held 2.45K shares in Iron Mountain as of September 2026, up by 594 shares quarter on quarter, and down 250.0Mn shares year over year.
Coastline Trust Co holds the largest position in IRM at 1.64K shares as of September 30, 2026, or 0.0% of shares outstanding.
The biggest buyers of Iron Mountain for the quarter ending September 2026 included Sarver Vrooman Wealth Advisors (610), Hickory Point Bank & Trust (200).
The biggest sellers of Iron Mountain for the quarter ending September 2026 included Coastline Trust Co (216).
According to Business Quant data, leading holders of IRM for September 2026 are Coastline Trust Co (1.64K), Sarver Vrooman Wealth Advisors (610), Hickory Point Bank & Trust (200).

Form 13F Holdings

1,161 Institutional Holders

Report period 30 Jun, 2026

Total shares held 260.94Mn

Of outstanding 87.64%

#	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
11	Sixth Street Partners Management Company, L.P.	0001812095	4,263,487	1.43%	▲4,263,487	0.00%	$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

Showing 1 to 20 of 1,161 holders