ATRIUM THERAPEUTICS INC (RNA) Institutional Ownership Changes & 13F Activity

ATRIUM THERAPEUTICS INC (RNA). Institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC Form 13F filings (Q4 2025). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions in the latest reporting period. Notable filers include Ra Capital Management, L.P., Janus Henderson Group Plc, Balyasny Asset Management L.P., Pentwater Capital Management Lp, and Avoro Capital Advisors Llc.

InstitutionTypeChange in sharesChange Position %SharesReported stock balancePortfolio quarterFiling date
Cornerstone Financial Management LlcBuy+11—11$793.00Q4 2025Aug 28, 2026
Ensign Peak Advisors, IncSell-458,464-78.9%122,393$8.83MQ4 2025Aug 18, 2026
Transmarket Holdings LpBuy+19,537—19,537$1.41MQ4 2025May 13, 2026
Z3 Capital Partners, LlcBuy+3,800—3,800$274.09KQ4 2025May 07, 2026
Bluefin Capital Management, LlcBuy+10,000—10,000$721.30KQ4 2025Apr 29, 2026
Hsbc Holdings PlcBuy+32,729—32,729$2.36MQ4 2025Mar 06, 2026
Td Capital Management LlcBuy+10—10$721.00Q4 2025Feb 26, 2026
Bell Investment Advisors, IncBuy+40—40$2.89KQ4 2025Feb 24, 2026
Virtu Financial LlcBuy+21,575—21,575$1.56MQ4 2025Feb 23, 2026
Corient Private Wealth LlcBuy+9,550—9,550$688.84KQ4 2025Feb 19, 2026
Raymond James Financial IncBuy+57,078—57,078$4.12MQ4 2025Feb 18, 2026
Newedge Advisors, LlcBuy+8,615—8,615$621.40KQ4 2025Feb 18, 2026
Mackenzie Financial CorpBuy+7,255—7,255$522.42KQ4 2025Feb 18, 2026
Ra Capital Management, L.P.Buy+8,641,031—8,641,031$623.28MQ4 2025Feb 17, 2026
Janus Henderson Group PlcBuy+6,939,503—6,939,503$500.56MQ4 2025Feb 17, 2026
Balyasny Asset Management L.P.Buy+6,040,590—6,040,590$435.71MQ4 2025Feb 17, 2026
Pentwater Capital Management LpBuy+6,026,500—6,026,500$434.69MQ4 2025Feb 17, 2026
Avoro Capital Advisors LlcBuy+5,455,000—5,455,000$393.47MQ4 2025Feb 17, 2026
Hbk Investments L PBuy+4,365,000—4,365,000$314.85MQ4 2025Feb 17, 2026
Bellevue Group AgBuy+2,630,969—2,630,969$189.77MQ4 2025Feb 17, 2026
Adage Capital Partners Gp, L.L.C.Buy+2,630,966—2,630,966$189.77MQ4 2025Feb 17, 2026
Millennium Management LlcBuy+2,157,270—2,157,270$155.60MQ4 2025Feb 17, 2026
Tig Advisors, LlcBuy+1,801,683—1,801,683$129.96MQ4 2025Feb 17, 2026
Citadel Advisors LlcBuy+1,592,429—1,592,429$114.86MQ4 2025Feb 17, 2026
Magnetar Financial LlcBuy+1,158,603—1,158,603$83.57MQ4 2025Feb 17, 2026
Fil LtdBuy+1,144,000—1,144,000$82.52MQ4 2025Feb 17, 2026
Qube Research & Technologies LtdBuy+1,105,830—1,105,830$79.76MQ4 2025Feb 17, 2026
Alliancebernstein L.P.Buy+1,047,410—1,047,410$75.55MQ4 2025Feb 17, 2026
Northern Trust CorpBuy+1,019,087—1,019,087$73.51MQ4 2025Feb 17, 2026
Casdin Capital, LlcBuy+1,000,000—1,000,000$72.13MQ4 2025Feb 17, 2026
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Frequently asked questions about RNA activity

  • Which institutional owners are buying RNA?

    Institutional owners buying RNA include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in RNA activity?

    "Buy" means an investor increased their reported position in RNA compared to the prior reporting period. This reflects growing exposure to ATRIUM THERAPEUTICS INC (RNA) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in RNA increasing?

    Institutional interest in RNA can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.