Insider Transactions Reported by 31 Insiders of CRESCENT BIOPHARMA, INC.

Symbol: CBIO on Nasdaq
Location: Waltham, MA

Quick Takeaways

CBIO - CRESCENT BIOPHARMA, INC. has 31 insiders with reported activity on this page.
Net insider value flow over the last year: +$19,999,999.
Recent transaction rows are available for direct filing-level review.

What Changed

Buy value: $19,999,999; sell value: $0.
Net share flow: +1,491,434.

Why This Matters

This page gives a plain-language issuer insider context before you inspect transaction-level evidence.
Use the filing links below to verify timestamps, codes, and ownership impacts directly from SEC forms.

Official SEC Source

Filed on Form 4

Issuer insider activity is sourced from SEC Forms 3, 4, and 5.

See Original Filing

Insider trading overview

Last 12 months

Net insider flow leans to buying over the last 12 months. Net value: +$19,999,999.

Buys

$19,999,999

Shares: 1,491,434

Insiders: 1

Sells

Shares: 0

Insiders: 0

Net

+$19,999,999

Shares: +1,491,434

Insiders: 1

Window (months)	Buy shares	Buy $	Sell $	Net $
0-3	0	$0	$0	$0
3-6	1,491,434	$19,999,999	$0	+$19,999,999
6-9	0	$0	$0	$0
9-12	0	$0	$0	$0

CRESCENT BIOPHARMA, INC. executives and other stock owners filed with the SEC include:

Name	Relationship	Holdings Value	Past Year Net Change	Change %	Valuation	Report Date
Fairmount Funds Management LLC	Director, 10%+ Owner	$60,557,872	+$19,999,999	+49%	Filing P/S	04 Dec 2025
Scott D. Sandell	10%+ Owner	$5,279,783			Mixed	25 Jan 2023
Joshua T. Brumm	Chief Executive Officer, Director	$4,878,636			Mixed	15 Dec 2025
Jonathan McNeill	President and COO	$2,408,381			Mixed	15 Dec 2025
Siren, L.L.C.	10%+ Owner	$2,294,139			Mixed	25 Jul 2024
Rachel K. King	Director	$1,545,582			Mixed	01 May 2024
Invus Public Equities, L.P.	10%+ Owner	$1,211,077			Filing P/S	07 Aug 2024
Christopher Grant Doughty	Chief Business Officer	$937,885			Mixed	15 Dec 2025
John L. Magnani	SVP of Research, CSO	$875,378			Mixed	11 Nov 2022
Chinmaya Rath	SVP and Chief Business Officer	$380,380			Mixed	12 Jan 2024
Jan Pinkas	Chief Scientific Officer	$339,405			Mixed	15 Dec 2025
Bruce S. Johnson	SVP & Chief Commercial Officer	$327,993			Mixed	12 Jan 2024
Ellie Eunkyung Im	Chief Medical Officer	$321,173			Mixed	15 Dec 2025
Daniel M. Junius	Director	$295,377			Mixed	01 May 2024
Richard William Scalzo	Chief Financial Officer	$292,883			Mixed	15 Dec 2025
Barbara Harlin Bispham	General Counsel and Corporate Secretary.	$277,803			Mixed	15 Dec 2025
Ryan Lynch	Treasurer, Senior Vice President of Finance and Chief Accounting Officer.	$186,660			Mixed	15 Dec 2025
Edwin Rock	Chief Medical Officer	$181,736			Filing P/S	20 Jun 2024
Patricia S. Andrews	Director	$138,315			Mixed	01 May 2024
Mark Alan Goldberg	Director	$108,975			Mixed	01 May 2024
Scott Koenig	Director	$86,730			Mixed	01 May 2024
Armand Girard	SVP, Chief Business Officer	$68,820			Mixed	11 Nov 2022
Brian M. Hahn	SVP Finance, CFO	$17,498			Filing P/S	18 Jun 2024
Jonathan Violin	Director	$14,598			Mixed	23 Jun 2025
BVF PARTNERS L P/IL	10%+ Owner	$13,100			Mixed	13 Jun 2025
Susan Moran	Director				Mixed	23 Jun 2025
Timothy R. Pearson	Director				Mixed	01 May 2024
Harout Semerjian	Chief Executive Officer, Director				Mixed	12 Jan 2024
David Charles Lubner	Director				Mixed	23 Jun 2025
Scott Thomas Jackson	Director				Mixed	01 May 2024
Alexandra Balcom	Director				Mixed	23 Jun 2025

Top shareholders of CRESCENT BIOPHARMA, INC. (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Ownership % is shown only when it is directly reported or safely comparable across share classes.

Methodology: rows are grouped by holder and ranked by the holder's primary source value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

Holder	Source	Role / Reporting	Ownership %	Shares	Holdings Value	12M Net Δ	As of	Details
Fairmount Funds Management LLC	13D/G 3/4/5 13F	Director, 10%+ Owner · Company	19%	5,643,482	$73,252,396	+$32,700,021	04 Dec 2025	13D/G 3/4/5 13F
FMR LLC	13D/G 13F	Company	15%	4,133,514	$49,932,849	$0	31 Dec 2025	13D/G 13F
BVF INC/IL	13F	Company	9.8%	2,748,763	$32,600,329	—	31 Dec 2025	13F
Venrock Healthcare Capital Partners III, L.P.	13D/G	—	9.5%	2,666,064	$29,460,007	$0	31 Dec 2025	13D/G
VR Adviser, LLC	13F	Company	7.6%	2,133,576	$25,304,211	—	31 Dec 2025	13F
ForGrowth III PA B.V.	13D/G	—	6.1%	1,677,852	$21,778,519	$0	08 Dec 2025	13D/G
1Globe Capital LLC	13D/G	—	10%	1,425,432	$20,839,816	+$7,729,886	07 Oct 2025	13D/G
FCPM III SERVICES B.V.	13F	Company	6%	1,677,852	$19,899,325	—	31 Dec 2025	13F
BIOTECHNOLOGY VALUE FUND L P	13D/G	BVF PARTNERS L P/IL	10%	1,387,863	$18,736,150	$0	30 Jun 2025	13D/G
Vestal Point Capital, LP	13F 13D/G	Company	5.4% from 13D/G	1,500,000	$17,790,000	—	31 Dec 2025	13F 13D/G
Opaleye Management Inc.	13F	Company	4.2%	1,178,300	$13,974,638	—	31 Dec 2025	13F
TANG CAPITAL MANAGEMENT LLC	13F 13D/G	Company	5% from 13D/G	872,398	$10,346,640	—	31 Dec 2025	13F 13D/G
Logos Global Management LP	13D/G 13F	Company	4.1%	575,000	$7,762,500	$0	30 Jun 2025	13D/G 13F
ADAR1 Capital Management, LLC	13F	Company	2.2%	606,000	$7,187,160	—	31 Dec 2025	13F
VANGUARD GROUP INC	13F	Company	2%	557,506	$6,612,021	—	31 Dec 2025	13F
Boxer Capital Management, LLC	13F	Company	1.6%	453,686	$5,380,716	—	31 Dec 2025	13F
Deep Track Capital, LP	13F	Company	1.6%	453,686	$5,380,716	—	31 Dec 2025	13F
PERCEPTIVE ADVISORS LLC	13F	Company	1.6%	453,686	$5,380,716	—	31 Dec 2025	13F
Scott D. Sandell	3/4/5	10%+ Owner	— class O/S missing	2,237,196	$5,279,783	—	25 Jan 2023	3/4/5
Joshua T. Brumm	3/4/5	Chief Executive Officer, Director	— mixed-class rows	503,984 mixed-class rows	$4,878,636	—	15 Dec 2025	3/4/5
NEXTBio Capital Management LP	13F	Company	1.3%	372,856	$4,422,072	—	31 Dec 2025	13F
RTW INVESTMENTS, LP	13F	Company	1.3%	372,856	$4,422,072	—	31 Dec 2025	13F
Remedium Capital Partners, LLC	13F	Company	2.6%	361,250	$4,284,000	—	31 Dec 2025	13F
PRICE T ROWE ASSOCIATES INC /MD/	13F	Company	1.2%	338,125	$4,011,000	—	31 Dec 2025	13F
DRIEHAUS CAPITAL MANAGEMENT LLC	13F	Company	1.1%	302,457	$3,587,140	—	31 Dec 2025	13F
Point72 Asset Management, L.P.	13F	Company	1.1%	300,000	$3,558,000	—	31 Dec 2025	13F
HEIGHTS CAPITAL MANAGEMENT, INC	13F	Company	0.94%	264,000	$3,131,040	—	31 Dec 2025	13F
Alyeska Investment Group, L.P.	13F	Company	0.94%	264,000	$3,108,992	—	31 Dec 2025	13F
Jonathan McNeill	3/4/5	President and COO	— mixed-class rows	237,736 mixed-class rows	$2,408,381	—	15 Dec 2025	3/4/5
Siren, L.L.C.	3/4/5	10%+ Owner	— class O/S missing	8,589,064	$2,294,139	—	25 Jul 2024	3/4/5
WELLINGTON MANAGEMENT GROUP LLP	13F	Company	0.51%	143,412	$1,626,774	—	31 Dec 2025	13F
Rachel K. King	3/4/5	Director	— mixed-class rows	555,194 mixed-class rows	$1,545,582	—	01 May 2024	3/4/5
TWO SIGMA INVESTMENTS, LP	13F	Company	0.45%	125,224	$1,485,157	—	31 Dec 2025	13F
BALYASNY ASSET MANAGEMENT L.P.	13F	Company	0.4%	111,715	$1,324,940	—	31 Dec 2025	13F
BlackRock, Inc.	13F	Company	0.39%	109,230	$1,295,468	—	31 Dec 2025	13F
Invus Public Equities, L.P.	3/4/5	10%+ Owner	— class O/S missing	6,317,565	$1,211,077	—	07 Aug 2024	3/4/5
GEODE CAPITAL MANAGEMENT, LLC	13F	Company	0.32%	91,079	$1,081,062	—	31 Dec 2025	13F
Stonepine Capital Management, LLC	13F	Company	0.31%	87,682	$1,039,909	—	31 Dec 2025	13F
Christopher Grant Doughty	3/4/5	Chief Business Officer	— mixed-class rows	121,049 mixed-class rows	$937,885	—	15 Dec 2025	3/4/5
Blackstone Inc.	13F	Company	0.27%	75,614	$896,782	—	31 Dec 2025	13F
Woodline Partners LP	13F	Company	0.26%	74,000	$877,640	—	31 Dec 2025	13F
John L. Magnani	3/4/5	SVP of Research, CSO	— class O/S missing	370,923	$875,378	—	11 Nov 2022	3/4/5
Burkehill Global Management, LP	13F	Company	0.26%	74,000	$844,340	—	31 Dec 2025	13F
Jefferies Financial Group Inc.	13F	Company	0.23%	64,244	$761,934	—	31 Dec 2025	13F
MILLENNIUM MANAGEMENT LLC	13F	Company	0.22%	61,882	$733,921	—	31 Dec 2025	13F
SUSQUEHANNA INTERNATIONAL GROUP, LLP	13F	Company	0.2%	57,048	$676,589	—	31 Dec 2025	13F
RENAISSANCE TECHNOLOGIES LLC	13F	Company	0.17%	46,700	$553,862	—	31 Dec 2025	13F
TWO SIGMA ADVISERS, LP	13F	Company	0.12%	32,500	$385,450	—	31 Dec 2025	13F
Chinmaya Rath	3/4/5	SVP and Chief Business Officer	— mixed-class rows	411,178 mixed-class rows	$380,380	—	12 Jan 2024	3/4/5
Jan Pinkas	3/4/5	Chief Scientific Officer	— mixed-class rows	92,532 mixed-class rows	$339,405	—	15 Dec 2025	3/4/5

Recent Insider Transactions by Companies or Individuals for CRESCENT BIOPHARMA, INC.

Showing up to 300 most recent insider transactions from the last 12 months.

Insider	Symbol	Class	Transaction	%	Value $	* Price $	Shares	Shares Owned	Date	Ownership
Jan Pinkas	GLYC	Ordinary Shares	Award				22,507	22,507	15 Dec 2025	Direct
Jan Pinkas	GLYC	Stock Option (Right to Buy)	Award				70,025	70,025	15 Dec 2025	Direct
Christopher Grant Doughty	GLYC	Ordinary Shares	Award	57.5%			22,714	62,194	15 Dec 2025	Direct
Christopher Grant Doughty	GLYC	Stock Option (Right to Buy)	Award				58,855	58,855	15 Dec 2025	Direct
Joshua T. Brumm	GLYC	Ordinary Shares	Award	20.5%			55,117	323,517	15 Dec 2025	Direct
Joshua T. Brumm	GLYC	Stock Option (Right to Buy)	Award				180,467	180,467	15 Dec 2025	Direct
Richard William Scalzo	GLYC	Ordinary Shares	Award				19,422	19,422	15 Dec 2025	Direct
Richard William Scalzo	GLYC	Stock Option (Right to Buy)	Award				57,688	57,688	15 Dec 2025	Direct
Jonathan McNeill	GLYC	Ordinary Shares	Award	19%			25,507	159,707	15 Dec 2025	Direct
Jonathan McNeill	GLYC	Stock Option (Right to Buy)	Award				78,029	78,029	15 Dec 2025	Direct
Ellie Eunkyung Im	GLYC	Ordinary Shares	Award				21,298	21,298	15 Dec 2025	Direct
Ellie Eunkyung Im	GLYC	Stock Option (Right to Buy)	Award				65,190	65,190	15 Dec 2025	Direct
Ryan Lynch	GLYC	Ordinary Shares	Award				12,378	12,378	15 Dec 2025	Direct
Ryan Lynch	GLYC	Stock Option (Right to Buy)	Award				33,512	33,512	15 Dec 2025	Direct
Barbara Harlin Bispham	GLYC	Ordinary Shares	Award				18,422	18,422	15 Dec 2025	Direct
Barbara Harlin Bispham	GLYC	Stock Option (Right to Buy)	Award				72,185	72,185	15 Dec 2025	Direct
Jonathan McNeill	GLYC	Stock Option (Right to Buy)	Award				172,836	172,836	08 Dec 2025	Direct
Joshua T. Brumm	GLYC	Stock Option (Right to Buy)	Award				345,672	345,672	08 Dec 2025	Direct
Fairmount Funds Management LLC	GLYC	Ordinary Shares	Purchase	98%	$18,237,600	$13.41	1,360,000	2,747,866	04 Dec 2025	By Fairmount Healthcare Fund II L.P.
Fairmount Funds Management LLC	GLYC	Pre-Funded Warrant (Right to Buy)	Purchase	8.03%	$1,762,399	$13.41	131,434	1,768,140	04 Dec 2025	By Fairmount Healthcare Fund II L.P.
Jan Pinkas	GLYC	Stock Option (Right to Buy)	Award				142,474	142,474	16 Jul 2025	Direct
Susan Moran	GLYC	Stock Option (Right to Buy)	Award				9,023	9,023	23 Jun 2025	Direct
Fairmount Funds Management LLC	GLYC	Stock Option (Right to Buy)	Award				9,023	9,023	23 Jun 2025	By: Peter Harwin
Jonathan Violin	GLYC	Stock Option (Right to Buy)	Award				9,023	9,023	23 Jun 2025	Direct
Alexandra Balcom	GLYC	Stock Option (Right to Buy)	Award				9,023	9,023	23 Jun 2025	Direct
David Charles Lubner	GLYC	Stock Option (Right to Buy)	Award				9,023	9,023	23 Jun 2025	Direct
Bvf Partners L P/Il	GLYC	Common Stock	Other				1,270,004	707,116	13 Jun 2025	Direct
Bvf Partners L P/Il	GLYC	Pre-Funded Warrants to Purchase Common Stock	Other				587,557	304,098	13 Jun 2025	Direct

* An asterisk sign (*) next to the price indicates that the price is likely invalid.