Dyne Therapeutics, Inc. (DYN) SEC Filings, Jul-Aug 2026

DYN reports a planned sale of 1,797 shares of common stock, with an indicated aggregate market value of $47,226.00, to be executed on or after August 13, 2026 on Nasdaq. The shares relate to equity compensation, including 4,062 shares tied to restricted stock units dated August 12, 2026.

The filing also lists prior activity over the past three months: on June 25, 2026, Erick Lucera is shown as having sold 2,362 shares of common stock for proceeds of $48,103.00. The notice provides advance disclosure of these intended and recent transactions.

Doug Kerr filed to sell up to 2,443 shares of DYN common stock through Stifel Nicolaus, with an indicated value of $64,203.00, in a transaction dated August 13, 2026 on Nasdaq. The filing references equity compensation awards of 5,312 and 3,000 restricted stock units and notes a prior sale of 887 shares for $16,263.00 on June 16, 2026.

Dyne Therapeutics, Inc. common stock is reported as beneficially owned by several affiliated Atlas Venture funds and associated entities in this amended Schedule 13G. Atlas Venture Fund XI and its related entities report beneficial ownership of 4,479,449 shares, the Opportunity Fund I entities report 975,931 shares, and the Opportunity Fund II entities report 1,344,719 shares of common stock. Based on 186,746,431 shares outstanding as of July 24, 2026, the filing states that the Fund XI entities each may be deemed to own 2.4% of the class, the Opportunity Fund entities 0.5%, and the Opportunity Fund II entities 0.7%. Collectively, the reporting persons may be deemed to beneficially own 6,800,099 shares, or 3.6% of the company’s outstanding common stock, while each reporting group indicates ownership of 5% or less of the class.

Janus Henderson Group Ltd. filed an amended beneficial ownership report stating that its affiliated asset managers may be deemed to beneficially own 11,997,738 shares of Dyne Therapeutics Inc. common stock, representing 7.3% of the class as of June 30, 2026. These shares are held in various client accounts referred to as Managed Portfolios, for which the asset managers exercise shared voting and dispositive power over all 11,997,738 shares, with no sole voting or dispositive power. The Managed Portfolios, not Janus Henderson, have the right to receive dividends and sale proceeds, and none of the individual portfolios owns more than five percent of Dyne Therapeutics’ common stock.

FMR LLC filed an amended beneficial ownership report for Dyne Therapeutics Inc. common stock. FMR LLC reports beneficial ownership of 11,206,999.89 shares, representing 6.8% of the outstanding common stock as of June 30, 2026. FMR LLC has sole voting power over 11,206,231.00 shares and sole dispositive power over 11,206,999.89 shares, with no shared voting or dispositive power.

Abigail P. Johnson is reported as having sole dispositive power over the same 11,206,999.89 shares, with no voting or shared powers. One or more other persons have rights to receive dividends or sale proceeds from these securities, but no such person holds an interest exceeding five percent of Dyne Therapeutics’ common stock.

Dyne Therapeutics reported second quarter 2026 results and detailed progress across its neuromuscular pipeline. The FDA accepted the Biologics License Application for z-rostudirsen in exon 51 Duchenne muscular dystrophy with Priority Review, setting a PDUFA target action date of January 21, 2027, and a global confirmatory Phase 3 FORZETTO trial is underway. In myotonic dystrophy type 1, Dyne completed enrollment of 71 participants in the registrational expansion cohort of the ACHIEVE trial for z-basivarsen, began dosing in the Phase 3 HARMONIA trial, and plans ACHIEVE topline data in the first quarter of 2027. The FDA also cleared an Investigational New Drug application for DYNE-302 in facioscapulohumeral muscular dystrophy. Financing actions included expanding a senior secured term loan facility with Hercules Capital to up to $400 million and completing an underwritten public offering of 21,045,000 shares at $20.50 per share for gross proceeds of approximately $431 million, supporting an expected cash runway into the second quarter of 2028.

Cash, cash equivalents and marketable securities were $898.5 million as of June 30, 2026, before the estimated $405.0 million of net proceeds from the July 2026 offering. Research and development expenses were $152.2 million and general and administrative expenses were $29.5 million for the quarter, compared with $99.2 million and $16.6 million, respectively, a year earlier. Net loss was $178.6 million, or $1.08 per basic and diluted share, versus $110.9 million, or $0.97 per share, for the prior-year quarter.

Dyne Therapeutics director Dirk Kersten, through ForDyne B.V., reported two indirect open-market sales totaling 261,460 shares of common stock on July 27, 2026, at weighted average prices of $25.5024 and $26.0428 per share. These trades were executed under a Rule 10b5-1 trading plan adopted by ForDyne on November 11, 2025. ForDyne is jointly owned by Forbion funds, and Kersten disclaims beneficial ownership of the shares except to the extent of his pecuniary interest.

Dyne Therapeutics is a clinical-stage neuromuscular company with no product revenue and a growing investment in late-stage programs. For the six months ended June 30, 2026, it recorded a net loss of $299.4 million, up from $226.2 million, driven by higher R&D of $253.2 million and G&A of $53.8 million, reflecting expanded manufacturing, pivotal trials and headcount.

Liquidity remains strong: at June 30, 2026 the company held $676.1 million in cash and cash equivalents, $222.4 million in marketable securities and $2.4 million in restricted cash. Long-term debt under a Hercules term loan totaled $200.0 million in principal (11.6% effective rate in the quarter), alongside a $14.2 million vendor financing balance, and stockholders’ equity was $702.2 million. A July 2026 follow-on equity offering added about $405.0 million of net proceeds, and management expects existing resources to fund operations, debt service and capital needs into the second quarter of 2028.

The lead DMD candidate z-rostudirsen has a biologics license application accepted with FDA priority review and a PDUFA action date of January 21, 2027; the confirmatory Phase 3 FORZETTO trial is underway. DM1 candidate z-basivarsen is in a registrational Phase 1/2 ACHIEVE cohort and Phase 3 HARMONIA; the expansion cohort is fully enrolled, with data intended to support a 2027 BLA and a potential U.S. launch in the first half of 2028. FSHD candidate DYNE-302 received IND clearance to start Phase 1, while Pompe candidate DYNE-401 and tau-targeting CNS conjugates remain in preclinical development.

BlackRock, Inc. reports beneficial ownership of 11,489,504 shares of Dyne Therapeutics, Inc. common stock, representing 7.0% of the outstanding class as of June 30, 2026. BlackRock has sole voting power over 11,273,443 shares and sole dispositive power over all 11,489,504 shares, with no shared voting or dispositive authority. The holdings are attributed to certain BlackRock business units, and various underlying clients have economic rights to dividends or sale proceeds, but no single client holds more than five percent of Dyne’s outstanding common shares.