Definium Therapeutics, Inc.: which funds bought and sold

Institutions that bought and sold Definium Therapeutics shares in Q2 2026, from the holdings they reported to the SEC on Form 13F for March 31, 2026 and June 30, 2026.

Between March 31, 2026 and June 30, 2026, 256 institutions that filed 13F reports for both quarters added to or opened positions in Definium Therapeutics, and 93 cut or closed them. Together they added a net 34.3M shares, +45.8% on what they held at the start of the quarter. Active managers and hedge funds on our list were net buyers of 27.5M shares (+87.2%); index fund managers were net buyers of 6.6M shares (+37.3%). 141 opened a new position and 29 sold out entirely.

Bought, Q2 2026 256 institutions, 141 of them new holders Sold, Q2 2026 93 institutions, 29 of them sold out

Net change, all compared +34.3M shares (+45.8%)

Net change, active managers +27.5M shares (+87.2%), 43 bought, 19 sold

Buyers versus sellers

institutions compared, 379

256 bought 30 93 sold

Active managers and hedge funds 43 bought · 19 sold · +27.5M

Index fund managers 12 bought · 0 sold · +6.6M

Other institutions 201 bought · 74 sold · +164K

Biggest buyers

by change in shares held

Biggest buyers
Institution	Change in shares	Shares June 30, 2026	Value
Capital World Investors Active manager	+5.4M New position	5.4M	$252M
Price T Rowe Associates Inc Active manager	+4.6M +6545.7%	4.7M	$219M
Capital International Investors Active manager	+3.0M New position	3.0M	$139M
FMR LLC Active manager	+2.9M +162.6%	4.8M	$224M
Blackrock, Inc. Index funds	+2.8M +32.5%	11.2M	$528M
Avoro Capital Advisors LLC Hedge fund	+2.2M +43.8%	7.2M	$338M
Alliancebernstein L.P. Active manager	+1.7M +1866.4%	1.8M	$34.1M
Wellington Management Group LLP Active manager	+1.6M +126.1%	2.9M	$139M
RA Capital Management, L.P. Hedge fund	+1.5M New position	1.5M	$70.6M
Geode Capital Management, LLC Index funds	+1.1M +46.1%	3.6M	$171M
Driehaus Capital Management LLC Active manager	+933K +15.8%	6.8M	$322M
Polar Capital Holdings PLC Active manager	+777K New position	777K	$36.6M
Vanguard Portfolio Management LLC Index funds	+776K +88.9%	1.6M	$77.5M
State Street Corp Index funds	+594K +24.0%	3.1M	$144M
Neuberger Berman Group LLC Active manager	+554K +415.5%	688K	$32.3M
BAMCO Inc Active manager	+520K New position	520K	$24.5M
Octagon Capital Advisors LP	+510K +20.9%	3.0M	$139M
Siren, L.L.C.	+500K +54.4%	1.4M	$66.8M
Franklin Resources Inc Active manager	+486K New position	486K	$22.9M
Great Point Partners LLC	+425K New position	425K	$20M

Biggest buyers, active managers and hedge funds
Institution	Change in shares	Shares June 30, 2026	Value
Capital World Investors Active manager	+5.4M New position	5.4M	$252M
Price T Rowe Associates Inc Active manager	+4.6M +6545.7%	4.7M	$219M
Capital International Investors Active manager	+3.0M New position	3.0M	$139M
FMR LLC Active manager	+2.9M +162.6%	4.8M	$224M
Avoro Capital Advisors LLC Hedge fund	+2.2M +43.8%	7.2M	$338M
Alliancebernstein L.P. Active manager	+1.7M +1866.4%	1.8M	$34.1M
Wellington Management Group LLP Active manager	+1.6M +126.1%	2.9M	$139M
RA Capital Management, L.P. Hedge fund	+1.5M New position	1.5M	$70.6M
Driehaus Capital Management LLC Active manager	+933K +15.8%	6.8M	$322M
Polar Capital Holdings PLC Active manager	+777K New position	777K	$36.6M

Biggest sellers

by change in shares held

Biggest sellers
Institution	Change in shares	Shares June 30, 2026	Value
Trails Edge Capital Partners, LP	−1.7M Sold out	0	—
Arrowmark Colorado Holdings LLC	−1.0M −64.6%	564K	$26.5M
Candriam S.C.A.	−679K −52.5%	614K	$28.9M
Millennium Management LLC Hedge fund	−581K −68.6%	266K	$12.5M
Stempoint Capital LP	−514K −78.9%	137K	$6.5M
Catalio Capital Management, LP	−475K −45.8%	563K	$26.5M
Orbimed Advisors LLC	−439K −54.6%	365K	$17.2M
Balyasny Asset Management L.P. Hedge fund	−377K −29.6%	898K	$42.2M
Patient Square Capital LP	−331K Sold out	0	—
Holocene Advisors, LP Hedge fund	−295K −27.1%	797K	$37.5M
Awm Investment Company, Inc.	−292K −27.1%	785K	$36.9M
Two Sigma Investments, LP Hedge fund	−280K −23.3%	922K	$43.4M
Deutsche Bank Ag\	−269K −65.3%	143K	$6.7M
Jane Street Group, LLC	−260K Sold out	0	—
Deep Track Capital, LP Hedge fund	−250K −8.3%	2.8M	$129M
Tri Locum Partners LP	−207K −55.9%	163K	$7.7M
Superstring Capital Management LP	−163K −46.4%	188K	$8.9M
Adage Capital Partners Gp, L.L.C. Hedge fund	−150K −13.0%	1.0M	$47M
Bit Capital Gmbh	−149K −53.8%	128K	$6M
Soviero Asset Management, LP	−140K Sold out	0	—

Biggest sellers, active managers and hedge funds
Institution	Change in shares	Shares June 30, 2026	Value
Millennium Management LLC Hedge fund	−581K −68.6%	266K	$12.5M
Balyasny Asset Management L.P. Hedge fund	−377K −29.6%	898K	$42.2M
Holocene Advisors, LP Hedge fund	−295K −27.1%	797K	$37.5M
Two Sigma Investments, LP Hedge fund	−280K −23.3%	922K	$43.4M
Deep Track Capital, LP Hedge fund	−250K −8.3%	2.8M	$129M
Adage Capital Partners Gp, L.L.C. Hedge fund	−150K −13.0%	1.0M	$47M
Squarepoint Ops LLC Hedge fund	−126K Sold out	0	—
Exoduspoint Capital Management, LP Hedge fund	−105K Sold out	0	—
Brevan Howard Capital Management LP Hedge fund	−55K −25.9%	157K	$7.4M
Caxton Associates LLP Hedge fund	−37K Sold out	0	—

New positions

largest by value

Institution	Shares	Value June 30, 2026
Capital World InvestorsActive manager	5.4M	$252M
Capital International InvestorsActive manager	3.0M	$139M
RA Capital Management, L.P.Hedge fund	1.5M	$70.6M
Polar Capital Holdings PLCActive manager	777K	$36.6M
BAMCO IncActive manager	520K	$24.5M
Franklin Resources IncActive manager	486K	$22.9M
Great Point Partners LLC	425K	$20M
Cormorant Asset Management, LPHedge fund	400K	$18.8M
Silverarc Capital Management, LLC	400K	$18.8M
Assetmark, Inc	397K	$18.7M

Sold out

largest by value

Institution	Shares	Value March 31, 2026
Trails Edge Capital Partners, LP	1.7M	$32.9M
Patient Square Capital LP	331K	$6.3M
Jane Street Group, LLC	260K	$4.9M
Soviero Asset Management, LP	140K	$2.6M
Squarepoint Ops LLCHedge fund	126K	$2.4M
Rosalind Advisors, Inc.	125K	$2.4M
Exoduspoint Capital Management, LPHedge fund	105K	$2M
HRT Financial LP	89K	$1.7M
Ikarian Capital, LLC	59K	$1.1M
Twinbeech Capital LP	42K	$795,690

Who holds the shares

13F holdings at June 30, 2026

Institutions reporting: 357
Ten largest holders: 48.2%
Index fund managers: 21.2%
Active managers and hedge funds: 51.4%

Buying and selling by type of institution, March 31, 2026 to June 30, 2026
Type	Bought	Sold	New	Sold out	Net change in shares	Net %
Active managers and hedge funds	43	19	21	7	+27.5M	+87.2%
Index fund managers	12	0	2	0	+6.6M	+37.3%
Other institutions	201	74	118	22	+164K	+0.6%

Active managers and hedge funds: a list we maintain of about 400 well-known stock-picking firms and hedge funds, matched by SEC registration number (CIK) and checked against the filer names each quarter. Index fund managers: the large index houses, such as BlackRock, Vanguard, State Street, Geode and Northern Trust. Every other filer (banks, brokers, wealth managers, pension funds, insurers and firms not on the list) counts as another institution. A firm that files under several SEC registrations appears once for each.

What these filings can and cannot tell you

Form 13F lists the long positions in US-listed shares held by investment managers with more than $100 million in such holdings. Managers file it up to 45 days after each quarter ends, so this page shows what funds held at the end of each quarter, not what they are doing now: a position may have changed since. Short positions, most derivatives and smaller managers are not included, and a cut can mean a fund lost clients or rebalanced rather than a view on Definium Therapeutics.

Only managers that filed a holdings report for both quarters are compared (379 here). 12 other holders are left out: first-time or late filers, firms that changed their SEC registration, and filings that withheld positions under confidential treatment, any of which would otherwise look like a new position or a sale. Figures are as reported by each manager in the SEC's quarterly 13F data sets; option positions are excluded.

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