Dyne Therapeutics (DYN) CEO's tax-driven sale to cover RSU taxes
Rhea-AI Filing Summary
Dyne Therapeutics, Inc. CEO & President John Cox reported a sale of 4,986 shares of Common Stock on August 13, 2026 at a weighted average price of $26.28 per share. The shares were automatically sold to satisfy tax withholding obligations arising from vesting of restricted stock units granted on February 12, 2026 under a restricted stock unit agreement that constitutes a “binding contract” consistent with the affirmative defense under Rule 10b5‑1, so the transaction is not a discretionary trade. Following this sale, Cox directly holds 363,165 shares, including 248,314 unvested RSUs, and indirectly holds 18,000 shares in each of four trusts for the benefit of a child of the reporting person.
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Insights
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Insider Trade Summary 10b5-1
Net Seller: 4,986 shares
Net Sell
5 txns
Insider
Cox John
Role
CEO & President
Sold
4,986 shs ($131K)
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Sale | Common Stock F1, F2, F3 | 4,986 | $26.28 | $131K |
| holding | Common Stock F4 | -- | -- | -- |
| holding | Common Stock F4 | -- | -- | -- |
| holding | Common Stock F4 | -- | -- | -- |
| holding | Common Stock F4 | -- | -- | -- |
Holdings After Transaction:
Common Stock — 363,165 shares (Direct);
Common Stock — 18,000 shares (Indirect, By Trust #1);
Common Stock — 18,000 shares (Indirect, By Trust #2);
Common Stock — 18,000 shares (Indirect, By Trust #3);
Common Stock — 18,000 shares (Indirect, By Trust #4)
Footnotes (4)
- F1. 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.
- F2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices within the range of $26.17 to $26.39, 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.
- F3. Includes 248,314 unvested RSUs.
- F4. These shares are held in a trust for the benefit of a child of the Reporting Person.
Key Figures
Shares sold: 4,986 shares
Weighted average sale price: $26.28 per share
Direct holdings after transaction: 363,165 shares
+4 more
7 metrics
Shares sold
4,986 shares
Common Stock sold on August 13, 2026
Weighted average sale price
$26.28 per share
Average price for 4,986 shares sold; individual trades $26.17–$26.39
Direct holdings after transaction
363,165 shares
Common Stock directly held by John Cox following the sale
Unvested RSUs included in direct holdings
248,314 RSUs
Unvested restricted stock units included in post-transaction direct holdings
Indirect holdings per trust
18,000 shares
Common Stock held in each of four trusts for a child of the reporting person
RSU grant date referenced
February 12, 2026
Grant date of RSUs whose vesting triggered the tax‑withholding sale
Sale price range
$26.17 to $26.39 per share
Range of prices for multiple transactions comprising the reported sale
Key Terms
restricted stock units, tax withholding obligations, Rule 10b5-1, weighted average price, +1 more
5 terms
restricted stock units financial
"vesting of restricted stock units granted to the Reporting Person"
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.
tax withholding obligations financial
"shares automatically sold by the Reporting Person to satisfy tax withholding obligations"
Rule 10b5-1 regulatory
"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.
binding contract regulatory
"restricted stock unit agreement constituting a "binding contract" consistent with"
FAQ
What did Dyne Therapeutics (DYN) CEO John Cox report in this Form 4?
John Cox reported an automatic sale of 4,986 Dyne Therapeutics (DYN) shares on August 13, 2026. The sale was to cover tax withholding obligations from vesting restricted stock units and was executed under a Rule 10b5‑1 binding contract.
Does John Cox have indirect holdings of Dyne Therapeutics (DYN) stock through trusts?
Yes. The Form 4 reports 18,000 Dyne Therapeutics shares held in each of four separate trusts. Each trust holds shares for the benefit of a child of the reporting person, and these positions are reported as indirect ownership.
AI-generated analysis. How Rhea-AI works. Not financial advice.
