155 institutional investment managers reported RNA positions in their Form 13F filings for Q2 2026, holding 15,491,867 shares worth $208M in total. Sessa Capital IM, L.P. reported the largest position.

Are funds buying or selling RNA?

In Q2 2026, 37 managers opened new RNA positions, 46 added, 34 trimmed and 44 sold out. Managers that filed in both quarters added a net 764,871 shares.

How current is this RNA 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.

Funds · RNA

Who owns RNA?

Institutional ownership of Atrium Therapeutics Inc. from Form 13F, Q2 2026

155 institutional managers reported holding Atrium Therapeutics Inc. (RNA) in Form 13F filings for Q2 2026, with 15,491,867 shares worth $208M. The largest reported holder was Sessa Capital IM, L.P. Managers that filed both quarters added a net 764,871 shares (+5.2%). 37 opened new positions and 44 sold out.

Funds holding: 155
Value held: $208M
New / sold out: 37 / 44
Net shares, same filers: +5.2%

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 RNA

Fund	Value	Share of 13F holdings	Shares	Move
Sessa Capital IM, L.P.	$20.2M	9.7%	1,500,000	Added
Price T Rowe Associates Inc	$19.8M	9.5%	1,472,984	Trimmed
BlackRock, Inc.	$19.5M	9.3%	1,447,476	Added
CRCM LP	$17.3M	8.3%	1,283,078	New
Vanguard Capital Management LLC	$9.8M	4.7%	730,831	Added
TIG Advisors, LLC	$7.6M	3.6%	561,533	Trimmed
Arbiter Partners Capital Management LLC	$7.0M	3.4%	522,576	Added
Cantor Fitzgerald, L. P.	$6.9M	3.3%	513,834	Added
Geode Capital Management, LLC	$5.2M	2.5%	386,929	Added
Two Sigma Investments, LP	$4.6M	2.2%	345,481	Added
Goldman Sachs Group Inc	$4.2M	2.0%	310,341	Trimmed
683 Capital Management, LLC	$4.0M	1.9%	300,000	Unchanged
State Street Corp	$3.7M	1.8%	271,762	Added
Slotnik Capital, LLC	$3.2M	1.5%	237,637	Added
Weiss Asset Management LP	$3.0M	1.4%	219,730	Trimmed
Millennium Management LLC	$2.7M	1.3%	200,559	Added
Schonfeld Strategic Advisors LLC	$2.7M	1.3%	199,158	Added
AQR Capital Management LLC	$2.3M	1.1%	172,235	New
Nexpoint Asset Management, L.p.	$2.0M	1.0%	150,025	Unchanged
Polar Asset Management Partners Inc.	$2.0M	1.0%	150,000	Added
Squarepoint Ops LLC	$2.0M	0.9%	146,743	Trimmed
Bracebridge Capital, LLC	$1.9M	0.9%	139,239	Unchanged
Nomura Holdings Inc	$1.8M	0.9%	137,394	Unchanged
Yakira Capital Management, Inc.	$1.8M	0.9%	133,047	Added
Bank of America Corp	$1.8M	0.9%	132,833	Trimmed

Share of 13F holdings is each fund's shares as a share of the 15,491,867 RNA shares all 13F filers reported, not of shares outstanding.

Biggest buyers in Q2 2026

CRCM LP New+$17.3M
Sessa Capital IM, L.P. Added+$12.8M
Arbiter Partners Capital Management LLC Added+$3.9M
Cantor Fitzgerald, L. P. Added+$3.7M
BlackRock, Inc. Added+$3.3M
AQR Capital Management LLC New+$2.3M
Two Sigma Investments, LP Added+$2.2M
DAFNA Capital Management LLC New+$1.7M
Norges Bank New+$1.7M
Anson Funds Management LP New+$1.7M

Biggest sellers in Q2 2026

Ra Capital Management, L.p. Sold out-$11.6M
Pentwater Capital Management LP Sold out-$8.1M
O'Connor Alternative Investments LLC Sold out-$7.7M
Farallon Capital Management, L.l.c. Sold out-$4.7M
Bellevue Group AG Sold out-$3.5M
Vanguard Portfolio Management LLC Trimmed-$3.3M
AQR Arbitrage LLC Sold out-$2.4M
Balyasny Asset Management L.P. Trimmed-$1.7M
Morgan Stanley Trimmed-$1.7M
Squarepoint Ops LLC Trimmed-$1.1M

The change in shares since the quarter before, adjusted for stock splits and priced at the Q2 2026 value per share. Funds bought $69.5M and sold $59.0M; 46 added and 34 trimmed.

Schedule 13D and 13G filings on RNA

Owners of more than 5% must file within days, so these can be newer than the 13F data.

2026-05-15RA CAPITAL MANAGEMENT, L.P. SCHEDULE 13G filed by Atrium Therapeutics Inc.Schedule 13G
2026-04-27BlackRock, Inc. SCHEDULE 13G filed by Atrium Therapeutics Inc.Schedule 13G
2026-04-08PRICE T ROWE ASSOCIATES INC /MD/ SCHEDULE 13G filed by Atrium Therapeutics Inc.Schedule 13G
2025-02-14JANUS HENDERSON GROUP PLC SCHEDULE 13G filed by Avidity Biosciences Inc.Schedule 13G

Questions about RNA ownership

Who owns RNA stock?: 155 institutional investment managers reported RNA positions in their Form 13F filings for Q2 2026, holding 15,491,867 shares worth $208M in total. Sessa Capital IM, L.P. reported the largest position.
Are funds buying or selling RNA?: In Q2 2026, 37 managers opened new RNA positions, 46 added, 34 trimmed and 44 sold out. Managers that filed in both quarters added a net 764,871 shares.
How current is this RNA 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 RNA by CUSIP. Options are left out. RNA news and filings · RNA insider trades · Top funds