Dyne Therapeutics (DYN) CEO’s 3,311-share sale is automatic tax withholding
Filing Impact
Filing Sentiment
Form Type
4
Rhea-AI Filing Summary
Dyne Therapeutics CEO John Cox reported an automatic tax-related sale of 3,311 shares of common stock. The shares were sold on May 13, 2026 at a weighted average price of $18.36 per share to satisfy tax withholding obligations tied to the vesting of restricted stock units granted on February 12, 2026.
The sale was executed under a restricted stock unit agreement described as a binding contract consistent with the Rule 10b5-1 affirmative defense, meaning it was not a discretionary trade. After this transaction, Cox directly holds 370,834 shares, including 268,645 unvested RSUs, and also reports indirect holdings through trusts for the benefit of a child.
Positive
- None.
Negative
- None.
Insider Trade Summary 10b5-1
Net Seller: 3,311 shares ($60,790)
Net Sell
5 txns
Insider
Cox John
Role
CEO & President
Sold
3,311 shs ($61K)
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Sale | Common Stock | 3,311 | $18.36 | $61K |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
Holdings After Transaction:
Common Stock — 370,834 shares (Direct, null);
Common Stock — 18,000 shares (Indirect, By Trust #1)
Footnotes (1)
- Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on February 12, 2026. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices within the range of $18.20 to $18.41, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote of this Form 4. Includes 268,645 unvested RSUs. These shares are held in a trust for the benefit of a child of the Reporting Person.
Key Figures
Shares sold: 3,311 shares
Average sale price: $18.36 per share
Post-transaction direct holdings: 370,834 shares
+2 more
5 metrics
Shares sold
3,311 shares
Automatic sale on May 13, 2026 for tax withholding
Average sale price
$18.36 per share
Weighted average price for the 3,311 shares sold
Post-transaction direct holdings
370,834 shares
Common stock directly held after the sale
Unvested RSUs
268,645 RSUs
Included within Cox’s direct holdings after the sale
Trust-held shares
18,000 shares
Common stock held indirectly in a trust for a child
Key Terms
restricted stock units, Rule 10b5-1, weighted average price, unvested RSUs, +1 more
5 terms
restricted stock units financial
"vesting of restricted stock units granted to the Reporting Person on February 12, 2026"
Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.
Rule 10b5-1 regulatory
"binding contract consistent with the affirmative defense to liability under Rule 10b5-1"
Rule 10b5-1 is a regulation that allows company insiders to buy or sell their shares at predetermined times, even if they have access to non-public information. It acts like setting a schedule in advance for transactions, helping prevent accusations of unfair trading. This rule provides a way for insiders to plan trades transparently, giving investors confidence that these transactions are not based on hidden information.
weighted average price financial
"The price reported in Column 4 is a weighted average price."
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
unvested RSUs financial
"Includes 268,645 unvested RSUs."
trust financial
"These shares are held in a trust for the benefit of a child of the Reporting Person."
FAQ
What insider transaction did Dyne Therapeutics (DYN) report for CEO John Cox?
Dyne Therapeutics reported that CEO John Cox had 3,311 shares of common stock sold. The sale was automatic to cover tax withholding obligations triggered by the vesting of previously granted restricted stock units, not a discretionary open-market trade by Cox.
Does John Cox have indirect Dyne Therapeutics (DYN) holdings through trusts?
Yes. The Form 4 notes that some Dyne Therapeutics shares are held indirectly in trusts for the benefit of a child of John Cox. These trust holdings are reported as indirect ownership separate from his 370,834 directly held shares following the tax-related sale.