DYN Dyne Therapeutics, Inc.

NASDAQ
$18.21

Dyne Therapeutics, Inc. (DYN) Insider Activity

What the officers, directors and large holders did with their own shares. Only open-market purchases and sales count toward the totals — grants, option exercises and shares withheld for tax are compensation mechanics, not decisions, and they're listed separately below.

Insider signal Bearish Selling ran elevated versus DYN's own trailing one-year pace, with 100% of sale value under a prearranged plan.
Cluster activity 0 buyers in the last 30 days 0 buyers in the last 90 days 6 sellers in the last 90 days
Insiders buying
0
0 transactions
Insiders selling
6
51 transactions
Purchases
$0
0 shares
Sales
$113.8M
4,773,031 shares
Net activity
-$113.8M
purchases less sales

How much of that selling was preplanned? 100% planned / 0% discretionary

10b5-1 plan sales $113.7M 49 transactions · 4,765,669 shares
Discretionary sales $166.2K 2 transactions · 7,362 shares

Largest single sale: $34.0M.

Where they traded

Buy Sell Dot area is proportional to transaction value.

Last open-market purchase: June 8, 2026 , by Posner Brian S .

Recent open-market activity

Date Insider Role Action Shares Price Value Held after
Cox John CEO & President Sell 10b5-1 5,658 $18.88 $106.8K 357,507 −1.6% of holding
Kerr Douglas Chief Medical Officer Sell 10b5-1 1,290 $18.88 $24.4K 162,564 −0.8% of holding
Friedl-Naderer Johanna Chief Commercial Officer Sell 10b5-1 185 $18.88 $3.5K 152,897 −0.1% of holding
Kerr Douglas Chief Medical Officer Sell 10b5-1 3,745 $24.35 $91.2K 163,854 −2.2% of holding
Friedl-Naderer Johanna Chief Commercial Officer Sell 10b5-1 900 $24.35 $21.9K 153,082 −0.6% of holding
Rhodes Jason P 3 fills Director Sell 10b5-1 2,160,516 $25.00 $54.0M 2,441,454 −46.9% of holding
Rhodes Jason P 3 fills Director Sell 10b5-1 426,412 $26.20 $11.2M 3,801,128 −10.1% of holding
Cox John CEO & President Sell 10b5-1 4,986 $26.28 $131.0K 363,165 −1.4% of holding
Lucera Erick Chief Financial Officer Sell 10b5-1 1,797 $26.28 $47.2K 119,766 −1.5% of holding
Kerr Douglas Chief Medical Officer Sell 10b5-1 1,556 $26.28 $40.9K 167,599 −0.9% of holding
Friedl-Naderer Johanna Chief Commercial Officer Sell 10b5-1 226 $26.28 $5.9K 153,982 −0.1% of holding
Kersten Dirk 2 fills Director Sell 10b5-1 261,460 $25.51 $6.7M 3,592,184 −6.8% of holding
Rhodes Jason P 6 fills Director Sell 10b5-1 292,211 $23.26 $6.8M 4,099,069 −6.7% of holding
Rhodes Jason P Director Sell 5,000 $23.61 $118.1K 2,962 −62.8% of holding
Rhodes Jason P 3 fills Director Sell 10b5-1 480,240 $22.79 $10.9M 4,223,448 −10.2% of holding
Rhodes Jason P 3 fills Director Sell 10b5-1 195,427 $21.14 $4.1M 4,476,487 −4.2% of holding
Rhodes Jason P 3 fills Director Sell 10b5-1 309,268 $21.28 $6.6M 4,579,456 −6.3% of holding
Rhodes Jason P 3 fills Director Sell 10b5-1 24,100 $21.10 $508.5K 4,742,410 −0.5% of holding
Lucera Erick Chief Financial Officer Sell 2,362 $20.37 $48.1K 121,563 −1.9% of holding
Rhodes Jason P 3 fills Director Sell 10b5-1 95,900 $21.02 $2.0M 4,755,109 −2% of holding
Rhodes Jason P 3 fills Director Sell 10b5-1 147,760 $21.13 $3.1M 4,805,639 −3% of holding
Kersten Dirk 2 fills Director Sell 10b5-1 73,286 $21.05 $1.5M 3,849,913 −1.9% of holding
Kersten Dirk Director Sell 10b5-1 190,676 $20.57 $3.9M 3,921,542 −4.6% of holding
Kersten Dirk Director Sell 10b5-1 46,901 $20.07 $941.4K 4,112,218 −1.1% of holding
Kersten Dirk Director Sell 10b5-1 37,454 $20.14 $754.3K 4,159,119 −0.9% of holding
Cox John CEO & President Sell 10b5-1 2,683 $18.33 $49.2K 368,151 −0.7% of holding
Kerr Douglas Chief Medical Officer Sell 10b5-1 887 $18.33 $16.3K 169,155 −0.5% of holding
Friedl-Naderer Johanna Chief Commercial Officer Sell 10b5-1 145 $18.33 $2.7K 154,208 −0.1% of holding

Form 4s are due within two business days of a transaction, so this is close to real time — unlike the quarterly 13F data on the Institutional tab. A single large sale often reflects a prearranged 10b5-1 plan rather than a fresh view, so read a pattern of sales rather than any one of them.