Person · CIK 1814189

Douglas Kerr

Head of R&D and CMO at Dyne Therapeutics

Earlier: Generation Bio

Source: Forms 3, 4, 5 and 144 on SEC EDGAR

Sold on Form 4$1.9M

Noticed on Form 144$299K

Bought on Form 4$0

Companies2

Holdings now

As reported after the latest Form 3, 4 or 5 at each company.

How these figures work

Options and RSUs are from the latest filing that lists them; earlier grants may also be held. Holdings can be out of date when a person stops filing.

Company	Security	Held	Shares or units	As of
Dyne Therapeutics DYN	Common Stock	Directly	170,564	Oct 20, 2026 · Filing · EDGAR
Dyne Therapeutics DYN	Stock option (right to buy) exercise $16.27, expires Oct 19, 2036, into Common Stock	Directly	12,000	Oct 20, 2026 · Filing · EDGAR
Generation Bio	Common Stock	Directly	385,628	Jan 29, 2024 · Filing · EDGAR

Sold and noticed by quarter

Sold (Form 4) Noticed (Form 144) Bought (Form 4)

Quarterly totals as a table

Quarter	Sold (Form 4)	Noticed (Form 144)
Q3 2026	$156K	$187K
Q2 2026	$45K	—
Q1 2026	$13K	—
Q4 2025	$18K	$18K
Q3 2025	$59K	$60K
Q2 2025	$18K	$18K
Q1 2025	$16K	$16K
Q3 2021	$89K	Not machine-readable
Q2 2021	$423K	Not machine-readable
Q1 2021	$1M	Not machine-readable

Form 144 notices went onto EDGAR as structured data on April 13, 2023. Earlier notices were filed on paper and cannot be read here, so those quarters show no noticed amount.

Planned sales (Form 144) and the sales that followed

Each Form 144 notice of a planned sale, grouped by broker and 10b5-1 plan, with the Form 4 sales we matched to it.

How we match

A Form 144 is a notice of a planned sale by an affiliate. SEC Tracker matches each notice to Form 4 sales by the same person at the same company within 90 days of the notice, up to the shares noticed. The match is our inference, not something either filing states.

Notice date	Noticed	Planned sale	Outcome	Links
Dyne Therapeutics DYN · Stifel Nicolaus & Company · No 10b5-1 plan stated · 7 notices
Sep 8, 2026	35 · ~$661	Sep 8, 2026	Not sold yet	Filing · EDGAR
Sep 4, 2026	5,000 · ~$122K	Sep 4, 2026	Sold as noticed Sold 5,035 in 2 sales, Sep 4 to Sep 8 · $116K Form 4	Filing · EDGAR
Aug 13, 2026	2,443 · ~$64K	Aug 13, 2026	Partly sold Sold 1,556 at $26.28 on Aug 13 · $41K likely match Form 4	Filing · EDGAR
Dec 5, 2025	880 · ~$18K	Dec 5, 2025	Sold as noticed Sold 880 at $20.72 on Dec 5 · $18K Form 4	Filing · EDGAR
Sep 4, 2025	4,552 · ~$60K	Sep 4, 2025	Partly sold Sold 4,425 in 2 sales, Sep 4 to Sep 5 · $59K likely match Form 4	Filing · EDGAR
Jun 5, 2025	1,342 · ~$18K	Jun 5, 2025	Sold as noticed Sold 1,342 at $13.35 on Jun 5 · $18K Form 4	Filing · EDGAR
Mar 5, 2025	1,343 · ~$16K	Mar 5, 2025	Sold as noticed Sold 1,343 at $11.83 on Mar 5 · $16K Form 4	Filing · EDGAR
Sales without a matching Form 144 · 19 sales No matching Form 144 found. Not every sale needs one: small sales and sales by people who are not affiliates are exempt.
—	—	—	Sold without notice Dyne Therapeutics (DYN): Sold 887 at $18.33 on Jun 16, 2026 · $16K (10b5-1 plan)	Filing · EDGAR
—	—	—	Sold without notice Dyne Therapeutics (DYN): Sold 1,564 at $18.36 on May 13, 2026 · $29K (10b5-1 plan)	Filing · EDGAR
—	—	—	Sold without notice Dyne Therapeutics (DYN): Sold 904 at $14.90 on Mar 5, 2026 · $13K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 1,889 at $25.39 on Jul 8, 2021 · $48K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 1,629 at $24.99 on Jul 8, 2021 · $41K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 3,321 at $30.68 on Apr 5, 2021 · $102K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 10,751 at $29.91 on Apr 5, 2021 · $322K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 100 at $35.58 on Mar 5, 2021 · $4K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 500 at $34.77 on Mar 5, 2021 · $17K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 400 at $33.75 on Mar 5, 2021 · $14K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 775 at $32.97 on Mar 5, 2021 · $26K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 4,315 at $31.87 on Mar 5, 2021 · $138K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 2,500 at $30.92 on Mar 5, 2021 · $77K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 2,677 at $29.68 on Mar 5, 2021 · $79K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 3,767 at $34.08 on Feb 8, 2021 · $128K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 7,500 at $33.01 on Feb 8, 2021 · $248K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 300 at $28.80 on Jan 11, 2021 · $9K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 4,721 at $28.05 on Jan 11, 2021 · $132K (10b5-1 plan)	Filing · EDGAR
—	—	—	Notice not machine-readable Generation Bio: Sold 6,246 at $27.17 on Jan 11, 2021 · $170K (10b5-1 plan)	Filing · EDGAR

Every transaction, by company

Each Form 3, 4 and 5 transaction in plain words, newest first.

How these figures work

Values are shares times the price each filing states; grants, exercises and gifts usually state no price. Held after is what the filing reports was held once the transaction was done, directly or through the named holder.

Dyne Therapeutics DYN Head of R&D and CMO · filings 2024 to 2026 · sold $326K · $299K noticed on Form 144

Date	Transaction	Shares	Price	Value	Held after	Source
Oct 20, 2026	Grant or award from the company	+8,000			170,564 direct	Filing · EDGAR
Oct 20, 2026	Grant or award from the company Stock option (right to buy)	+12,000			12,000 direct	Filing · EDGAR
Sep 8, 2026	Sale under a 10b5-1 plan	−1,290	$18.88	$24K	162,564 direct	Filing · EDGAR
Sep 4, 2026	Sale under a 10b5-1 plan	−3,745	$24.35	$91K	163,854 direct	Filing · EDGAR
Aug 13, 2026	Sale under a 10b5-1 plan	−1,556	$26.28	$41K	167,599 direct	Filing · EDGAR
Jun 16, 2026	Sale under a 10b5-1 plan	−887	$18.33	$16K	169,155 direct	Filing · EDGAR
May 13, 2026	Sale under a 10b5-1 plan	−1,564	$18.36	$29K	170,042 direct	Filing · EDGAR
Mar 5, 2026	Sale under a 10b5-1 plan	−904	$14.90	$13K	171,606 direct	Filing · EDGAR
Feb 12, 2026	Grant or award from the company	+85,000			172,510 direct	Filing · EDGAR
Feb 12, 2026	Grant or award from the company Stock option (right to buy)	+130,000			130,000 direct	Filing · EDGAR
Dec 5, 2025	Sale under a 10b5-1 plan	−880	$20.72	$18K	87,510 direct	Filing · EDGAR
Sep 5, 2025	Sale under a 10b5-1 plan	−873	$13.41	$12K	88,390 direct	Filing · EDGAR
Sep 4, 2025	Sale under a 10b5-1 plan	−3,552	$13.27	$47K	89,263 direct	Filing · EDGAR
Jul 16, 2025	Grant or award from the company Stock option (right to buy)	+65,110			65,110 direct	Filing · EDGAR
Jun 5, 2025	Sale under a 10b5-1 plan	−1,342	$13.35	$18K	92,815 direct	Filing · EDGAR
Mar 5, 2025	Sale under a 10b5-1 plan	−1,343	$11.83	$16K	94,157 direct	Filing · EDGAR
Dec 4, 2024	Grant or award from the company	+48,000			95,500 direct	Filing · EDGAR
Dec 4, 2024	Grant or award from the company Stock option (right to buy)	+76,600			76,600 direct	Filing · EDGAR
Sep 3, 2024	Grant or award from the company	+47,500			47,500 direct	Filing · EDGAR
Sep 3, 2024	Grant or award from the company Stock Option (Right to Buy)	+150,300			150,300 direct	Filing · EDGAR

Generation Bio Chief medical officer · filings 2020 to 2024 · sold $1.6M

Date	Transaction	Shares	Price	Value	Held after	Source
Jan 29, 2024	Option or RSU exercised or converted	+5,021			387,104 direct	Filing · EDGAR
Jan 29, 2024	Shares withheld for tax or exercise price	−1,476	$1.90	$3K	385,628 direct	Filing · EDGAR
Jan 29, 2024	Option or RSU exercised or converted Restricted Stock Units	−5,021			0 direct	Filing · EDGAR
Jan 15, 2024	Option or RSU exercised or converted	+7,437			380,286 direct	Filing · EDGAR
Jan 15, 2024	Shares withheld for tax or exercise price	−2,577	$1.91	$5K	377,709 direct	Filing · EDGAR
Jan 15, 2024	Option or RSU exercised or converted	+6,694			384,403 direct	Filing · EDGAR
Jan 15, 2024	Shares withheld for tax or exercise price	−2,320	$1.91	$4K	382,083 direct	Filing · EDGAR
Jan 15, 2024	Option or RSU exercised or converted Restricted Stock Units	−7,437			7,437 direct	Filing · EDGAR
Jan 15, 2024	Option or RSU exercised or converted Restricted Stock Units	−6,694			20,081 direct	Filing · EDGAR
Oct 15, 2023	Option or RSU exercised or converted	+7,437			372,587 direct	Filing · EDGAR
Oct 15, 2023	Shares withheld for tax or exercise price	−2,183	$3.24	$7K	370,404 direct	Filing · EDGAR
Oct 15, 2023	Option or RSU exercised or converted Restricted Stock Units	−7,437			7,437 direct	Filing · EDGAR
Jul 15, 2023	Option or RSU exercised or converted	+7,437			367,333 direct	Filing · EDGAR
Jul 15, 2023	Shares withheld for tax or exercise price	−2,183	$5.08	$11K	365,150 direct	Filing · EDGAR
Jul 15, 2023	Option or RSU exercised or converted Restricted Stock Units	−7,437			14,874 direct	Filing · EDGAR
Apr 15, 2023	Option or RSU exercised or converted	+7,437			358,963 direct	Filing · EDGAR
Apr 15, 2023	Shares withheld for tax or exercise price	−2,183	$4.50	$10K	356,780 direct	Filing · EDGAR
Apr 15, 2023	Option or RSU exercised or converted Restricted Stock Units	−7,437			22,311 direct	Filing · EDGAR
Jan 20, 2023	Grant or award from the company Stock Option (right to buy)	+53,550			53,550 direct	Filing · EDGAR
Jan 20, 2023	Grant or award from the company Restricted Stock Units	+26,775			26,775 direct	Filing · EDGAR
Jan 15, 2023	Option or RSU exercised or converted	+7,438			354,104 direct	Filing · EDGAR
Jan 15, 2023	Shares withheld for tax or exercise price	−2,578	$5.10	$13K	351,526 direct	Filing · EDGAR
Jan 15, 2023	Option or RSU exercised or converted Restricted Stock Units	−7,438			29,748 direct	Filing · EDGAR
Oct 15, 2022	Option or RSU exercised or converted	+7,438			346,985 direct	Filing · EDGAR
Oct 15, 2022	Shares withheld for tax or exercise price	−2,184	$5.61	$12K	344,801 direct	Filing · EDGAR
Oct 15, 2022	Option or RSU exercised or converted Restricted Stock Units	−7,438			37,186 direct	Filing · EDGAR
Jul 15, 2022	Option or RSU exercised or converted	+14,876			343,914 direct	Filing · EDGAR
Jul 15, 2022	Shares withheld for tax or exercise price	−4,367	$7.18	$31K	339,547 direct	Filing · EDGAR
Jul 15, 2022	Option or RSU exercised or converted Restricted Stock Units	−14,876			44,624 direct	Filing · EDGAR
Jan 21, 2022	Grant or award from the company Stock Option (right to buy)	+119,000			119,000 direct	Filing · EDGAR
Jan 21, 2022	Grant or award from the company Restricted Stock Units	+59,500			59,500 direct	Filing · EDGAR
Jul 8, 2021	Option or RSU exercised or converted	+3,518	$5.16	$18K	330,076 direct	Filing · EDGAR
Jul 8, 2021	Sale under a 10b5-1 plan	−1,629	$24.99	$41K	328,447 direct	Filing · EDGAR
Jul 8, 2021	Sale under a 10b5-1 plan	−1,889	$25.39	$48K	326,558 direct	Filing · EDGAR
Jul 8, 2021	Option or RSU exercised or converted Stock Option (right to buy)	−3,518			38,699 direct	Filing · EDGAR
Apr 5, 2021	Option or RSU exercised or converted	+14,072	$5.16	$73K	340,630 direct	Filing · EDGAR
Apr 5, 2021	Sale under a 10b5-1 plan	−10,751	$29.91	$322K	329,879 direct	Filing · EDGAR
Apr 5, 2021	Sale under a 10b5-1 plan	−3,321	$30.68	$102K	326,558 direct	Filing · EDGAR
Apr 5, 2021	Option or RSU exercised or converted Stock Option (right to buy)	−14,072			42,217 direct	Filing · EDGAR
Mar 5, 2021	Option or RSU exercised or converted	+11,267	$4.59	$52K	337,825 direct	Filing · EDGAR
Mar 5, 2021	Sale under a 10b5-1 plan	−2,677	$29.68	$79K	335,148 direct	Filing · EDGAR
Mar 5, 2021	Sale under a 10b5-1 plan	−2,500	$30.92	$77K	332,648 direct	Filing · EDGAR
Mar 5, 2021	Sale under a 10b5-1 plan	−4,315	$31.87	$138K	328,333 direct	Filing · EDGAR
Mar 5, 2021	Sale under a 10b5-1 plan	−775	$32.97	$26K	327,558 direct	Filing · EDGAR
Mar 5, 2021	Sale under a 10b5-1 plan	−400	$33.75	$14K	327,158 direct	Filing · EDGAR
Mar 5, 2021	Sale under a 10b5-1 plan	−500	$34.77	$17K	326,658 direct	Filing · EDGAR
Mar 5, 2021	Sale under a 10b5-1 plan	−100	$35.58	$4K	326,558 direct	Filing · EDGAR
Mar 5, 2021	Option or RSU exercised or converted Stock Option (right to buy)	−11,267			89,959 direct	Filing · EDGAR
Feb 8, 2021	Option or RSU exercised or converted	+11,267	$4.59	$52K	337,825 direct	Filing · EDGAR
Feb 8, 2021	Sale under a 10b5-1 plan	−7,500	$33.01	$248K	330,325 direct	Filing · EDGAR
Feb 8, 2021	Sale under a 10b5-1 plan	−3,767	$34.08	$128K	326,558 direct	Filing · EDGAR
Feb 8, 2021	Option or RSU exercised or converted Stock Option (right to buy)	−11,267			101,226 direct	Filing · EDGAR
Jan 22, 2021	Grant or award from the company Stock Option (right to buy)	+73,500			73,500 direct	Filing · EDGAR
Jan 11, 2021	Option or RSU exercised or converted	+11,267	$4.59	$52K	337,825 direct	Filing · EDGAR
Jan 11, 2021	Sale under a 10b5-1 plan	−6,246	$27.17	$170K	331,579 direct	Filing · EDGAR
Jan 11, 2021	Sale under a 10b5-1 plan	−4,721	$28.05	$132K	326,858 direct	Filing · EDGAR
Jan 11, 2021	Sale under a 10b5-1 plan	−300	$28.80	$9K	326,558 direct	Filing · EDGAR
Jan 11, 2021	Option or RSU exercised or converted Stock Option (right to buy)	−11,267			112,493 direct	Filing · EDGAR

All 39 Forms 3, 4, 5 and 144

Filed	Form	Company	Links
Oct 22, 2026	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Sep 8, 2026	Form 144	Dyne Therapeutics DYN	Filing · EDGAR
Sep 8, 2026	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Sep 4, 2026	Form 144	Dyne Therapeutics DYN	Filing · EDGAR
Aug 17, 2026	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Aug 13, 2026	Form 144	Dyne Therapeutics DYN	Filing · EDGAR
Jun 17, 2026	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
May 14, 2026	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Mar 6, 2026	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Feb 17, 2026	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Dec 5, 2025	Form 144	Dyne Therapeutics DYN	Filing · EDGAR
Dec 5, 2025	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Sep 8, 2025	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Sep 4, 2025	Form 144	Dyne Therapeutics DYN	Filing · EDGAR
Jul 18, 2025	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Jun 6, 2025	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Jun 5, 2025	Form 144	Dyne Therapeutics DYN	Filing · EDGAR
Mar 7, 2025	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Mar 5, 2025	Form 144	Dyne Therapeutics DYN	Filing · EDGAR
Dec 6, 2024	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Sep 3, 2024	Form 4	Dyne Therapeutics DYN	Filing · EDGAR
Sep 3, 2024	Form 3	Dyne Therapeutics DYN	Filing · EDGAR
Jan 31, 2024	Form 4	Generation Bio	Filing · EDGAR
Jan 17, 2024	Form 4	Generation Bio	Filing · EDGAR
Oct 17, 2023	Form 4	Generation Bio	Filing · EDGAR
Jul 18, 2023	Form 4	Generation Bio	Filing · EDGAR
Apr 18, 2023	Form 4	Generation Bio	Filing · EDGAR
Jan 24, 2023	Form 4	Generation Bio	Filing · EDGAR
Jan 18, 2023	Form 4	Generation Bio	Filing · EDGAR
Oct 18, 2022	Form 4	Generation Bio	Filing · EDGAR
Jul 19, 2022	Form 4	Generation Bio	Filing · EDGAR
Jan 25, 2022	Form 4	Generation Bio	Filing · EDGAR
Jul 12, 2021	Form 4	Generation Bio	Filing · EDGAR
Apr 7, 2021	Form 4	Generation Bio	Filing · EDGAR
Mar 9, 2021	Form 4	Generation Bio	Filing · EDGAR
Feb 10, 2021	Form 4	Generation Bio	Filing · EDGAR
Feb 5, 2021	Form 4	Generation Bio	Filing · EDGAR
Jan 13, 2021	Form 4	Generation Bio	Filing · EDGAR
Jun 11, 2020	Form 3	Generation Bio	Filing · EDGAR

Every figure is as filed with the SEC on Forms 3, 4, 5 and 144. Holdings are the amounts reported after each person's latest filing at each company and can be out of date. Matching a Form 144 notice to Form 4 sales is SEC Tracker's inference from owner, company, dates and share counts, not something the filings state. Not investment advice. Not affiliated with the U.S. SEC.