Atrium Therapeutics, Inc. (RNA) — Institutional Holders, Q2 2026

156 institutional investment managers reported a RNA position on SEC Form 13F-HR for the quarter ended June 30, 2026, with a combined reported value of $192.0M. Every filer is listed below, ranked by position value, 100 per page; this page shows ranks 1 to 100. Put and call option positions are excluded, and a firm filing several lots or share classes is shown once with its total.

← RNA stock profile

RNA in Q2 2026: what funds did

Funds that filed a 13F for both Q1 2026 and Q2 2026, by what they did with the common stock. Share counts are adjusted for any split between the two quarters; dollar figures are the change in shares at this quarter’s price.

New positions

Added to

Trimmed

Sold out

Biggest buyers

Sessa Capital IM, L.P.Added · +948,609 sh+$12.8M
CRCMNew · +583,255 sh+$7.8M
BlackRockAdded · +242,185 sh+$3.3M
AQR CAPITAL MANAGEMENTNew · +172,235 sh+$2.3M
TWO SIGMA INVESTMENTSAdded · +166,921 sh+$2.2M

Biggest sellers

RA CAPITAL MANAGEMENT, L.P.Sold out · -864,102 sh-$11.6M
Pentwater Capital ManagementSold out · -602,649 sh-$8.1M
O'Connor Alternative InvestmentsSold out · -578,011 sh-$7.8M
FARALLON CAPITAL MANAGEMENTSold out · -349,360 sh-$4.7M
Bellevue Group AGSold out · -263,096 sh-$3.5M

RNA 13F holders ranked 1–100 of 156

Institutional investors reporting a position in Atrium Therapeutics, Inc. on SEC Form 13F-HR for Q2 2026, ranked by reported value.
#	Institution	Shares	Value	% of portfolio	QoQShares vs Q1 2026
1	Sessa Capital IM, L.P.#1 · 1,500,000 sh	1,500,000	$20.2M	0.34%	+172.0%
2	PRICE T ROWE ASSOCIATES#2 · 1,472,984 sh	1,472,984	$19.8M	<0.01%	-5.2%
3	BlackRock#3 · 1,447,476 sh	1,447,476	$19.5M	<0.01%	+20.1%
4	VANGUARD CAPITAL MANAGEMENT#4 · 730,831 sh	730,831	$9.8M	<0.01%	+16.6%
5	CRCM#5 · 583,255 sh	583,255	$7.8M	5.44%	New
6	TIG Advisors#6 · 561,533 sh	561,533	$7.6M	0.33%	-7.6%
7	GEODE CAPITAL MANAGEMENT#7 · 386,929 sh	386,929	$5.2M	<0.01%	+21.0%
8	TWO SIGMA INVESTMENTS#8 · 345,481 sh	345,481	$4.6M	<0.01%	+93.5%
9	GOLDMAN SACHS GROUP#9 · 310,341 sh	310,341	$4.2M	<0.01%	-11.3%
10	683 Capital Management#10 · 300,000 sh	300,000	$4.0M	0.20%	0.0%
11	STATE STREET#11 · 271,762 sh	271,762	$3.7M	<0.01%	+5.7%
12	Arbiter Partners Capital Management#12 · 261,288 sh	261,288	$3.5M	1.85%	+13.6%
13	CANTOR FITZGERALD, L. P.#13 · 256,917 sh	256,917	$3.5M	0.04%	+9.0%
14	Slotnik Capital#14 · 237,637 sh	237,637	$3.2M	0.83%	+31.3%
15	Weiss Asset Management#15 · 219,730 sh	219,730	$3.0M	0.03%	-8.7%
16	MILLENNIUM MANAGEMENT#16 · 200,559 sh	200,559	$2.7M	<0.01%	+5.1%
17	Schonfeld Strategic Advisors#17 · 199,158 sh	199,158	$2.7M	<0.01%	+22.4%
18	AQR CAPITAL MANAGEMENT#18 · 172,235 sh	172,235	$2.3M	<0.01%	New
19	NEXPOINT ASSET MANAGEMENT, L.P.#19 · 150,025 sh	150,025	$2.0M	0.13%	0.0%
20	Polar Asset Management Partners#20 · 150,000 sh	150,000	$2.0M	0.03%	+114.3%
21	Squarepoint Ops#21 · 146,743 sh	146,743	$2.0M	<0.01%	-36.6%
22	Bracebridge Capital#22 · 139,239 sh	139,239	$1.9M	0.03%	0.0%
23	NOMURA#23 · 137,394 sh	137,394	$1.8M	<0.01%	0.0%
24	Yakira Capital Management#24 · 133,047 sh	133,047	$1.8M	0.51%	+5.1%
25	BANK OF AMERICA#25 · 132,833 sh	132,833	$1.8M	<0.01%	-2.5%
26	CHARLES SCHWAB INVESTMENT MANAGEMENT#26 · 130,217 sh	130,217	$1.8M	<0.01%	+11.7%
27	TUDOR INVESTMENT ET AL#27 · 129,591 sh	129,591	$1.7M	<0.01%	+81.6%
28	DAFNA Capital Management#28 · 128,000 sh	128,000	$1.7M	0.33%	New
29	Creek Drive Management Group#29 · 127,600 sh	127,600	$1.7M	0.83%	+6.3%
30	NORGES BANK#30 · 126,575 sh	126,575	$1.7M	<0.01%	—
31	Anson Funds Management#31 · 125,000 sh	125,000	$1.7M	0.10%	New
32	NORTHERN#32 · 119,781 sh	119,781	$1.6M	<0.01%	+21.5%
33	ExodusPoint Capital Management#33 · 117,275 sh	117,275	$1.6M	0.01%	New
34	Trium Capital LLP#34 · 113,278 sh	113,278	$1.5M	—	New
35	TD ASSET MANAGEMENT#35 · 111,200 sh	111,200	$1.5M	<0.01%	0.0%
36	VANGUARD FIDUCIARY#36 · 109,961 sh	109,961	$1.5M	<0.01%	+15.6%
37	JANE STREET GROUP#37 · 109,810 sh	109,810	$1.5M	<0.01%	+450.3%
38	Athos Capital Ltd#38 · 107,965 sh	107,965	$1.5M	0.52%	0.0%
39	AWM Investment Company#39 · 107,500 sh	107,500	$1.4M	0.13%	+115.0%
40	BALYASNY ASSET MANAGEMENT L.P.#40 · 105,875 sh	105,875	$1.4M	<0.01%	-55.0%
41	Marble Bar Asset Management LLP#41 · 103,849 sh	103,849	$1.4M	0.97%	-29.4%
42	VANGUARD PORTFOLIO MANAGEMENT#42 · 101,195 sh	101,195	$1.4M	<0.01%	-70.6%
43	ADAGE CAPITAL PARTNERS GP, L.L.C.#43 · 100,000 sh	100,000	$1.3M	<0.01%	-45.5%
44	BlueCrest Capital Management Ltd#44 · 100,000 sh	100,000	$1.3M	0.04%	New
45	CREDIT INDUSTRIEL ET COMMERCIAL#45 · 89,723 sh	89,723	$1.2M	0.08%	+290.1%
46	Groupe la Francaise#46 · 80,273 sh	80,273	$1.1M	<0.01%	+170.3%
47	FIL Ltd#47 · 76,500 sh	76,500	$1.0M	<0.01%	-2.5%
48	Caption Management#48 · 75,277 sh	75,277	$1.0M	<0.01%	-27.3%
49	CITADEL ADVISORS#49 · 67,639 sh	67,639	$909.7K	<0.01%	-38.5%
50	MANUFACTURERS LIFE INSURANCE COMPANY, THE#50 · 62,853 sh	62,853	$845.4K	<0.01%	+0.8%
51	ADAR1 Capital Management#51 · 57,688 sh	57,688	$775.9K	0.04%	0.0%
52	FRANKLIN RESOURCES#52 · 56,699 sh	56,699	$762.6K	<0.01%	New
53	JACOBS LEVY EQUITY MANAGEMENT#53 · 53,992 sh	53,992	$726.2K	<0.01%	New
54	ODDO BHF ASSET MANAGEMENT SAS#54 · 45,090 sh	45,090	$606.5K	0.03%	0.0%
55	CAXTON ASSOCIATES LLP#55 · 44,230 sh	44,230	$594.9K	0.01%	0.0%
56	ALETHEA CAPITAL MANAGEMENT#56 · 43,758 sh	43,758	$588.5K	0.24%	0.0%
57	CANADA PENSION PLAN INVESTMENT BOARD#57 · 41,970 sh	41,970	$564.5K	<0.01%	0.0%
58	MORGAN STANLEY#58 · 41,942 sh	41,942	$564.1K	0.00%	-74.6%
59	Saba Capital Management, L.P.#59 · 39,640 sh	39,640	$533.2K	0.01%	0.0%
60	Bank of New York Mellon#60 · 39,252 sh	39,252	$527.9K	<0.01%	-10.2%
61	Y-Intercept (Hong Kong) Ltd#61 · 35,103 sh	35,103	$472.1K	—	New
62	KENNEDY CAPITAL MANAGEMENT#62 · 34,979 sh	34,979	$470.5K	<0.01%	+2.9%
63	FMR#63 · 33,532 sh	33,532	$451.0K	0.00%	+14.5%
64	Moran Wealth Management#64 · 33,320 sh	33,320	$448.2K	—	New
65	BOUSSARD & GAVAUDAN GESTION SAS#65 · 32,845 sh	32,845	$447.2K	0.02%	—
66	LMR Partners LLP#66 · 32,500 sh	32,500	$437.1K	<0.01%	0.0%
67	LOS ANGELES CAPITAL MANAGEMENT#67 · 31,477 sh	31,477	$423.4K	<0.01%	New
68	Nuveen#68 · 31,071 sh	31,071	$417.9K	<0.01%	+22.8%
69	Jump Financial#69 · 31,017 sh	31,017	$417.2K	<0.01%	New
70	Quantinno Capital Management#70 · 27,418 sh	27,418	$368.8K	<0.01%	+120.2%
71	Twin Securities#71 · 26,517 sh	26,517	$356.7K	0.16%	-46.9%
72	Odyssean#72 · 21,233 sh	21,233	$285.6K	0.05%	New
73	Brevan Howard Capital Management#73 · 20,834 sh	20,834	$280.2K	<0.01%	-34.2%
74	Fractal Investments#74 · 20,000 sh	20,000	$269.0K	0.03%	0.0%
75	UBS Group AG#75 · 19,572 sh	19,572	$263.2K	0.00%	-60.7%
76	HEALTHCARE OF ONTARIO PENSION PLAN FUND#76 · 18,590 sh	18,590	$250.0K	<0.01%	-9.7%
77	Vestcor#77 · 17,499 sh	17,499	$235.0K	<0.01%	0.0%
78	WELLS FARGO & COMPANY#78 · 17,451 sh	17,451	$234.7K	0.00%	+52.9%
79	ALLIANCEBERNSTEIN L.P.#79 · 17,110 sh	17,110	$228.8K	<0.01%	+31.9%
80	RHUMBLINE ADVISERS#80 · 16,579 sh	16,579	$223.0K	<0.01%	+10.9%
81	BLUEFIN CAPITAL MANAGEMENT#81 · 16,011 sh	16,011	$215.3K	0.05%	New
82	RENAISSANCE TECHNOLOGIES#82 · 14,971 sh	14,971	$201.4K	<0.01%	New
83	DEUTSCHE BANK AG\#83 · 14,967 sh	14,967	$201.3K	<0.01%	+49.4%
84	Invesco Ltd.#84 · 14,174 sh	14,174	$190.6K	0.00%	+39.1%
85	Jupiter Topco#85 · 13,833 sh	13,833	$185.6K	<0.01%	—
86	AlphaCentric Advisors#86 · 13,478 sh	13,478	$181.3K	0.15%	+1.4%
87	AXQ CAPITAL#87 · 11,377 sh	11,377	$153.0K	0.02%	New
88	KESTRA PRIVATE WEALTH SERVICES#88 · 10,370 sh	10,370	$139.5K	<0.01%	New
89	MetLife Investment Management#89 · 10,283 sh	10,283	$138.3K	<0.01%	+16.3%
90	Corsicana#90 · 9,820 sh	9,820	$132.1K	0.06%	+22.8%
91	JPMORGAN CHASE#91 · 9,388 sh	9,388	$128.1K	0.00%	-22.0%
92	BNP PARIBAS FINANCIAL MARKETS#92 · 7,901 sh	7,901	$106.3K	0.00%	-4.4%
93	CITIGROUP#93 · 6,685 sh	6,685	$89.9K	0.00%	+947.8%
94	MIRAE ASSET GLOBAL ETFS Ltd.#94 · 6,602 sh	6,602	$88.8K	<0.01%	-30.4%
95	Vanguard Global Advisers#95 · 5,585 sh	5,585	$75.1K	0.00%	0.0%
96	Russell Investments Group, Ltd.#96 · 4,475 sh	4,475	$60.2K	<0.01%	+16.6%
97	Skandinaviska Enskilda Banken AB (publ)#97 · 4,400 sh	4,400	$59.2K	<0.01%	New
98	Walleye Trading#98 · 3,978 sh	3,978	$53.5K	<0.01%	+9.6%
99	Erste Asset Management GmbH#99 · 3,600 sh	3,600	$49.1K	<0.01%	0.0%
100	Quantbot Technologies#100 · 3,614 sh	3,614	$48.6K	<0.01%	New

Funds that sold out of RNA in Q2 2026 (45)

Held RNA at the end of Q1 2026 and filed a Q2 2026 13F without it. Not in the list above, because they no longer hold it. Largest prior position first.

Institutions that held RNA in Q1 2026 and reported no position in Q2 2026.
Institution	Shares sold	Value in Q1 2026
RA CAPITAL MANAGEMENT, L.P.864,102 sh	864,102	$11.6M
Pentwater Capital Management602,649 sh	602,649	$8.1M
O'Connor Alternative Investments578,011 sh	578,011	$7.7M
FARALLON CAPITAL MANAGEMENT349,360 sh	349,360	$4.7M
Bellevue Group AG263,096 sh	263,096	$3.5M
AQR Arbitrage179,713 sh	179,713	$2.4M
Neuberger Berman Group69,294 sh	69,294	$926.5K
Quarry66,651 sh	66,651	$891.1K
Westchester Capital Management55,236 sh	55,236	$738.5K
HIGHBRIDGE CAPITAL MANAGEMENT40,986 sh	40,986	$555.4K
FIFTH LANE CAPITAL35,999 sh	35,999	$481.3K
MARSHALL WACE, LLP33,691 sh	33,691	$450.4K
Woodline Partners28,845 sh	28,845	$385.7K
Cannon Global Investment Management25,087 sh	25,087	$335.4K
Point72 Asset Management, L.P.22,708 sh	22,708	$303.6K
Fortress Investment Group22,033 sh	22,033	$294.6K
Grantham, Mayo, Van Otterloo15,444 sh	15,444	$206.5K
Susquehanna Portfolio Strategies13,110 sh	13,110	$175.3K
PUBLIC SECTOR PENSION INVESTMENT BOARD12,882 sh	12,882	$172.2K
AlphaGrep UK Ltd11,870 sh	11,870	$158.7K
SUSQUEHANNA INTERNATIONAL GROUP, LLP11,343 sh	11,343	$151.7K
Magnetar Financial10,512 sh	10,512	$140.5K
Centiva Capital5,895 sh	5,895	$78.8K
QUADRANT CAPITAL GROUP632 sh	632	$53.2K
DIADEMA PARTNERS2,512 sh	2,512	$33.6K
MAI Capital Management1,293 sh	1,293	$17.3K
NATIXIS1,292 sh	1,292	$17.3K
Federation des caisses Desjardins du Quebec810 sh	810	$10.8K
Mint Tower Capital Management B.V.781 sh	781	$10.0K
PUBLIC EMPLOYEES RETIREMENT ASSOCIATION OF COLORADO780 sh	780	$10.0K
VAN ECK ASSOCIATES472 sh	472	$6.0K
KBC Group NV337 sh	337	$5.0K
Mitsubishi UFJ Asset Management , Ltd.331 sh	331	$4.4K
Persistent Asset Partners Ltd283 sh	283	$3.8K
Westside Investment Management120 sh	120	$1.6K
FIFTH THIRD BANCORP59 sh	59	$794.00
ASSETMARK34 sh	34	$455.00
Advisory Services Network12 sh	12	$160.00
NORTHWESTERN MUTUAL WEALTH MANAGEMENT4 sh	4	$53.00
MassMutual Private Wealth & , FSB2 sh	2	$27.00
Bell Investment Advisors2 sh	2	$27.00
Root Financial Partners1 sh	1	$13.00
Bare Financial Services1 sh	1	$13.00
Cornerstone Financial Management1 sh	1	$13.00
BESSEMER GROUP9 sh	9	$0.00

Source: Form 13F-HR filings on SEC EDGAR, Q2 2026. Values are as reported by each manager at quarter end. “% of portfolio” is the position’s share of the manager’s total reported 13F value for the same quarter. “New” means the manager filed a 13F for Q1 2026 without this position; a dash means no comparison is available. Where a manager’s own filing is internally inconsistent its value is withheld and it is listed last. 13F data shows reported holdings, not recommendations.