Atrium Therapeutics RNA Institutional Ownership

NASDAQ RNA

$8.26 -0.14 (-1.67%)

At close: Oct 29, 2026 · 4:00 PM EDT

Institutions by Trading Activity

155 Institutions

Increased 87 56.1%

Unchanged 33 21.3%

Reduced 35 22.6%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

83.49%

▼-2.77 pp QoQ

Shares Held by Institutions

14.28Mn

of 17.11Mn outstanding

▼-3.21% QoQ

Shares Outstanding

17.11Mn

2.82Mn held outside 13F filers

Institutional Investors

155

filed 13F for Jun 2026

▼-6 vs prior quarter

Net Shares Added (QoQ)

-473.45K

distributed since last quarter

Value of Holdings

$117.97Mn

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 Oct 10, 2026

Atrium Therapeutics, Inc. (NASDAQ:RNA) was reported as a holding by 155 institutional investors in 13F filings for the quarter ended June 30, 2026.

Collectively, these holders controlled 83.49% of Atrium Therapeutics' outstanding shares in Q2 2026, down from 86.26% in Q1 2026.
Total shares held in Atrium Therapeutics fell 3.21% versus Q1 2026.
Of these 155 holders, 87 added to their positions, 35 reduced their stakes and 33 left their positions unchanged.
Altogether, institutional holders owned 14.28Mn RNA shares at the end of Q2 2026, down 473.45K from the prior quarter.
Sessa Capital IM, L.P. held the largest position in RNA at 1.5Mn shares as of June 30, 2026, or 8.77% of shares outstanding.
Among holders that already owned Atrium Therapeutics, the biggest buyers in Q2 2026 were Sessa Capital IM, L.P. (+948.61K shares), BlackRock, Inc. (+242.19K shares), Two Sigma Investments, LP (+166.92K shares), Vanguard Capital Management LLC (+103.96K shares) and Jane Street Group, LLC (+89.86K shares).
The biggest cuts to RNA positions during Q2 2026 came from Vanguard Portfolio Management LLC (-243.17K shares), Balyasny Asset Management L.P. (-129.24K shares), Morgan Stanley (-123.09K shares), Squarepoint Ops LLC (-84.72K shares) and Adage Capital Partners GP, L.L.C. (-83.58K shares).
Business Quant data shows the 10 biggest positions in Atrium Therapeutics as of Q2 2026 were held by Sessa Capital IM, L.P. (1.5Mn shares), T. Rowe Price Associates Inc (1.47Mn shares), BlackRock, Inc. (1.45Mn shares), Vanguard Capital Management LLC (730.83K shares), CRCM LP (583.25K shares), TIG Advisors, LLC (561.53K shares), Geode Capital Management, LLC (386.93K shares), Two Sigma Investments, LP (345.48K shares), Goldman Sachs Group Inc (310.34K shares) and 683 Capital Management, LLC (300K shares).

Form 13F Holdings

155 Institutional Holders

Report period 30 Jun, 2026

Total shares held 14.28Mn

Of outstanding 83.49%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	Sessa Capital IM, L.P.	0001595849	1,500,000	8.77%	▲948,609	+172.04%	$20.18Mn
2	PRICE T ROWE ASSOCIATES INC /MD/	0000080255	1,472,984	8.61%	▼80,226	-5.17%	$19.81K
3	BlackRock, Inc.	0002012383	1,447,476	8.46%	▲242,185	+20.09%	$19.47Mn
4	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	730,831	4.27%	▲103,962	+16.58%	$9.83Mn
5	CRCM LP	0001483234	583,255	3.41%	▲583,255	0.00%	$7.84Mn
6	TIG Advisors, LLC	0001358253	561,533	3.28%	▼46,019	-7.57%	$7.55Mn
7	GEODE CAPITAL MANAGEMENT, LLC	0001214717	386,929	2.26%	▲67,098	+20.98%	$5.21Mn
8	TWO SIGMA INVESTMENTS, LP	0001179392	345,481	2.02%	▲166,921	+93.48%	$4.65Mn
9	Goldman Sachs Group Inc	0000886982	310,341	1.81%	▼39,609	-11.32%	$4.17Mn
10	683 Capital Management, LLC	0001404574	300,000	1.75%	0	0.00%	$4.04Mn
11	State Street Corp	0000093751	271,762	1.59%	▲14,676	+5.71%	$3.66Mn
12	Arbiter Partners Capital Management LLC	0001513193	261,288	1.53%	▲31,288	+13.60%	$3.51Mn
13	CANTOR FITZGERALD, L. P.	0001024896	256,917	1.50%	▲21,280	+9.03%	$3.46Mn
14	Slotnik Capital, LLC	0001963764	237,637	1.39%	▲56,692	+31.33%	$3.20Mn
15	Weiss Asset Management LP	0001357550	219,730	1.28%	▼20,971	-8.71%	$2.96Mn
16	MILLENNIUM MANAGEMENT LLC	0001273087	200,559	1.17%	▲9,700	+5.08%	$2.70Mn
17	Schonfeld Strategic Advisors LLC	0001665241	199,158	1.16%	▲36,399	+22.36%	$2.68Mn
18	AQR CAPITAL MANAGEMENT LLC	0001167557	172,235	1.01%	▲172,235	0.00%	$2.32Mn
19	NEXPOINT ASSET MANAGEMENT, L.P.	0001469877	150,025	0.88%	0	0.00%	$2.02Mn
20	Polar Asset Management Partners Inc.	0001326389	150,000	0.88%	▲80,000	+114.29%	$2.02Mn

Showing 1 to 20 of 155 holders