Insider Transactions Reported by 18 Insiders of Cyclerion Therapeutics, Inc.

Symbol: CYCN on Nasdaq
Location: Cambridge, MA

Quick Takeaways

CYCN - Cyclerion Therapeutics, Inc. has 18 insiders with reported activity on this page.
No net insider buy/sell flow is currently reported for the last year.
Recent transaction rows are available for direct filing-level review.

What Changed

No meaningful buy/sell imbalance is currently visible in the one-year window.
Activity will update as new Forms 3/4/5 are filed.

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.

Source Evidence

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

Insider buy and sell flow is broadly balanced over the last 12 months. No Buy or Sell transactions have been reported since 18 Apr 2025.

Buys

Shares: 0

Insiders: 0

Sells

Shares: 0

Insiders: 0

Net

Shares: 0

Insiders: 0

Window (months)	Buy $	Sell $	Net $
0-3	$0	$0	$0
3-6	$0	$0	$0
6-9	$0	$0	$0
9-12	$0	$0	$0

Cyclerion Therapeutics, Inc. executives and other stock owners filed with the SEC include:

Name	Relationship	Holdings Value	Valuation	Report Date
Peter M. Hecht	Director, 10%+ Owner	$1,538,006	Mixed	25 Mar 2025
Regina M. Graul	President and Chief Executive Officer, Director	$340,529	Mixed	05 Aug 2024
Terrance McGuire	Director	$142,624	Mixed	30 Nov 2023
Errol B. Desouza	Director	$101,850	Mixed	30 Nov 2023
Michael J. Higgins	Director	$84,535	Mixed	25 Mar 2025
Steven Hyman	Director	$67,900	Mixed	30 Nov 2023
Dina Katabi	Director	$67,900	Mixed	30 Nov 2023
Slate Path Capital LP	10%+ Owner	$0	Mixed	21 Nov 2024
Stephanie Lovell	Director		Mixed	14 Jun 2022
Andreas Busch	Chief Scientific Officer		Mixed	20 Jan 2022
Kevin Churchwell	Director		Mixed	24 Jun 2021
Ole Isacson	Director		Mixed	14 Jun 2022
George H. Conrades	Director		Mixed	14 Jun 2022
Cheryl Gault	Chief Operating Officer		Mixed	20 Jan 2022
Rhonda M. Chicko	Chief Financial Officer		Mixed	07 Aug 2025
Michael Mendelsohn	Director		Mixed	14 Jun 2022
Anjeza Gjino	Chief Financial Officer		Mixed	20 Jan 2022
Marsha Fanucci	Director		Mixed	14 Jun 2022

Top shareholders of Cyclerion Therapeutics, 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
Peter M. Hecht	13D/G 3/4/5	Director, 10%+ Owner	28%	1,028,086	$3,803,918	$0	25 Mar 2025	13D/G 3/4/5
J. WOOD CAPITAL ADVISORS LLC	13D/G	—	5.4%	181,818	$496,363	$0	25 Mar 2025	13D/G
American Endowment Foundation	13D/G	—	4.9%	133,026	$492,196	$0	31 Dec 2024	13D/G
TYNDALL CAPITAL PARTNERS L P	13D/G	—	4.8%	155,187	$487,287	-$30,113	30 Jun 2025	13D/G
Regina M. Graul	3/4/5	President and Chief Executive Officer, Director	— mixed-class rows	156,152 mixed-class rows	$340,529	—	05 Aug 2024	3/4/5
Siren, L.L.C.	13F	Individual	3.4%	115,603	$146,816	—	31 Dec 2025	13F
Terrance McGuire	3/4/5	Director	— class O/S missing	42,010	$142,624	—	30 Nov 2023	3/4/5
Errol B. Desouza	3/4/5	Director	— class O/S missing	30,000	$101,850	—	30 Nov 2023	3/4/5
Michael J. Higgins	3/4/5	Director	— class O/S missing	30,740	$84,535	—	25 Mar 2025	3/4/5
Dina Katabi	3/4/5	Director	— class O/S missing	20,000	$67,900	—	30 Nov 2023	3/4/5
Steven Hyman	3/4/5	Director	— class O/S missing	20,000	$67,900	—	30 Nov 2023	3/4/5
GEODE CAPITAL MANAGEMENT, LLC	13F	Company	1.3%	43,302	$55,006	—	31 Dec 2025	13F
TWO SIGMA INVESTMENTS, LP	13F	Company	1.2%	41,555	$52,775	—	31 Dec 2025	13F
TWO SIGMA ADVISERS, LP	13F	Company	0.84%	28,300	$35,941	—	31 Dec 2025	13F
VANGUARD GROUP INC	13F	Company	0.7%	23,490	$29,832	—	31 Dec 2025	13F
BlackRock, Inc.	13F	Company	0.5%	16,797	$21,332	—	31 Dec 2025	13F
FMR LLC	13D/G 13F	Company	0.2%	4,740	$17,538	$0	31 Dec 2024	13D/G 13F
XTX Topco Ltd	13F	Company	0.3%	10,027	$12,734	—	31 Dec 2025	13F
CITIGROUP INC	13F	Company	0.24%	8,204	$10,419	—	31 Dec 2025	13F
Tower Research Capital LLC (TRC)	13F	Company	0.09%	3,154	$4,006	—	31 Dec 2025	13F
UBS Group AG	13F	Company	0.01%	376	$478	—	31 Dec 2025	13F
GROUP ONE TRADING LLC	13F	Company	0.01%	192	$244	—	31 Dec 2025	13F
OSAIC HOLDINGS, INC.	13F	Company	0%	130	$165	—	31 Dec 2025	13F
BANK OF AMERICA CORP /DE/	13F	Company	0%	107	$136	—	31 Dec 2025	13F
Activest Wealth Management	13F	Company	0%	100	$127	—	31 Dec 2025	13F
MAI Capital Management	13F	Company	0%	100	$127	—	31 Dec 2025	13F
WHI TRUST Co LLC	13F	Company	0%	72	$91	—	31 Dec 2025	13F
BNP PARIBAS FINANCIAL MARKETS	13F	Company	0%	5	$6	—	31 Dec 2025	13F
MORGAN STANLEY	13F	Company	0%	1	$2	—	31 Dec 2025	13F
Andreas Busch	3/4/5	Chief Scientific Officer	— class O/S missing	135,000	—	—	20 Jan 2022	3/4/5
Anjeza Gjino	3/4/5	Chief Financial Officer	— class O/S missing	135,000	—	—	20 Jan 2022	3/4/5
Cheryl Gault	3/4/5	Chief Operating Officer	— class O/S missing	135,000	—	—	20 Jan 2022	3/4/5
Rhonda M. Chicko	3/4/5	Chief Financial Officer	— class O/S missing	25,000	—	—	07 Aug 2025	3/4/5
George H. Conrades	3/4/5	Director	— class O/S missing	20,000	—	—	14 Jun 2022	3/4/5
Marsha Fanucci	3/4/5	Director	— class O/S missing	20,000	—	—	14 Jun 2022	3/4/5
Michael Mendelsohn	3/4/5	Director	— class O/S missing	20,000	—	—	14 Jun 2022	3/4/5
Ole Isacson	3/4/5	Director	— class O/S missing	20,000	—	—	14 Jun 2022	3/4/5
Stephanie Lovell	3/4/5	Director	— class O/S missing	20,000	—	—	14 Jun 2022	3/4/5
Kevin Churchwell	3/4/5	Director	— class O/S missing	10,000	—	—	24 Jun 2021	3/4/5

Recent Insider Transactions by Companies or Individuals for Cyclerion Therapeutics, 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
Rhonda M. Chicko	CYCN	Stock Option (Right to Buy)	Award				25,000	25,000	07 Aug 2025	Direct

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