Dyne Therapeutics Announces Pricing of Upsized $350.0 Million Public Offering of Common Stock

Rhea-AI Summary

Dyne Therapeutics (Nasdaq: DYN) priced an upsized underwritten public offering of 18,980,478 common shares at $18.44 per share, expected to raise $350.0 million in gross proceeds before fees. The offering is expected to close on or about December 11, 2025, subject to customary closing conditions.

Dyne sold all shares in the offering and granted underwriters a 30-day option to purchase up to an additional 2,847,071 shares at the public offering price, less underwriting discounts and commissions.

Positive

• Gross proceeds of $350.0 million
• Offering upsized to 18,980,478 shares
• Underwriters include Morgan Stanley, Jefferies, Stifel, Guggenheim

Negative

• All offered shares are being sold by Dyne, causing shareholder dilution
• 30-day overallotment could add 2,847,071 shares outstanding
• Close is subject to customary conditions, not guaranteed on Dec 11, 2025

Key Figures

Offering size $350.0 million Gross proceeds from Dec 2025 common stock offering

Shares offered 18,980,478 shares Primary common stock sold by Dyne in this deal

Offering price $18.44 per share Public offering price for December 2025 deal

Underwriter option period 30 days Duration of option to buy additional shares

Underwriter option shares 2,847,071 shares Additional common shares available under 30-day option

Expected closing date December 11, 2025 Anticipated closing of the public offering

Pre-news share price $18.44 Last price before article, matching offering price

1-day price move -16.94% Change in DYN prior to publication of this pricing news

Market Reality Check

$18.44 Last Close

Volume Volume 6,339,213 is elevated with relative volume at 2.25x the 2,821,238 share 20-day average ahead of the offering. high

Technical Shares traded above the 200-day MA, with price at $18.44 versus MA(200) of $13.18 before this offering pricing.

Peers on Argus

While DYN fell 16.94%, key biotech peers showed modest moves: SRPT -1.29%, IMCR -3.60%, PROK -5.96%, MESO +0.54%, HRMY -0.14%, indicating a company-specific reaction.

Historical Context

Date	Event	Sentiment	Move	Catalyst
2025-12-08	Equity offering	Negative	+9.5%	Proposed $300M stock offering with 30-day underwriter option.
2025-12-08	Clinical results	Positive	+9.5%	Phase 1/2 DELIVER REC met primary endpoint with higher dystrophin.
2025-11-05	Earnings update	Negative	-2.9%	Q3 2025 net loss of $108.0M and ongoing R&D investment reported.
2025-11-03	Investor conferences	Positive	+6.8%	Announcement of multiple upcoming healthcare investor conference appearances.
2025-10-06	Clinical data	Positive	-3.1%	One-year ACHIEVE data showed sustained functional gains in DM1 patients.

Pattern Detected

Recent news has drawn mixed reactions, with offerings sometimes sold and sometimes bid up, and clinical updates not uniformly rewarded.

Recent Company History

Over the last few months, Dyne reported multiple milestones. In Q3 2025, it highlighted cash of $791.9M and a net loss of $108.0M, alongside progress toward BLA filings. Clinical updates from ACHIEVE and DELIVER showed functional improvements and favorable safety. The company also executed prior equity offerings in mid‑2025 and a proposed offering on Dec 8, 2025. Today’s upsized pricing follows that proposal and the recent positive DELIVER topline data.

Market Pulse Summary

This announcement detailed the pricing of an upsized common stock offering, with $350.0M in gross proceeds at $18.44 per share and an underwriter option for more shares. It follows recent positive clinical and financial updates in 2025. Investors may focus on how the added capital supports planned BLAs and trials, the cumulative impact of repeat offerings on ownership dilution, and execution against upcoming regulatory and clinical milestones.

Key Terms

underwritten public offering financial

"announced the pricing of an upsized underwritten public offering of 18,980,478"

An underwritten public offering is when a company sells new shares of its stock to the public with the help of a financial firm, called an underwriter. The underwriter agrees to buy all the shares upfront, reducing the company's risk, and then sells them to investors. This process helps companies raise money quickly and confidently from a wide range of buyers.

prospectus supplement regulatory

"This offering is being made only by means of a prospectus supplement and"

A prospectus supplement is an additional document provided alongside a company's main offering details, offering updated or extra information about a specific financial product being sold. It helps investors understand the latest terms, risks, and details of the investment, similar to how an update or revision clarifies or expands on original instructions, ensuring they have current and complete information before making a decision.

shelf registration statement regulatory

"pursuant to a shelf registration statement on Form S-3 that was previously"

A shelf registration statement is a document a company files with regulators that allows it to sell shares or bonds quickly when it’s a good time to raise money. It’s like having a pre-approved plan ready so the company can act fast without going through lengthy paperwork each time they want to sell, making fundraising more flexible.

form s-3 regulatory

"pursuant to a shelf registration statement on Form S-3 that was previously"

Form S-3 is a legal document companies use to register their stock sales with the government, making it easier and faster for them to raise money by selling shares to investors. It’s like having a pre-approved shopping list that lets a company quickly sell new shares when they need funds, without going through a lengthy approval process each time.

book-running managers financial

"Morgan Stanley, Jefferies, Stifel and Guggenheim Securities are acting as joint book-running managers"

Book-running managers are the main banks or financial firms that organize and oversee a company's sale of new stocks or bonds. They help set the price, decide how many to sell, and coordinate the process to make sure everything runs smoothly. Their role is important because they guide the company through the complex process of raising money from investors.

AI-generated analysis. Not financial advice.

WALTHAM, Mass., Dec. 09, 2025 (GLOBE NEWSWIRE) -- Dyne Therapeutics, Inc. (Nasdaq: DYN), a clinical-stage company focused on delivering functional improvement for people living with genetically driven neuromuscular diseases, today announced the pricing of an upsized underwritten public offering of 18,980,478 shares of its common stock at a public offering price of $18.44 per share. The gross proceeds to Dyne from the offering, before deducting underwriting discounts and commissions and offering expenses payable by Dyne, are expected to be $350.0 million. All shares in the offering are being sold by Dyne. The offering is expected to close on or about December 11, 2025, subject to customary closing conditions. In addition, Dyne has granted the underwriters a 30-day option to purchase up to an additional 2,847,071 shares of its common stock at the public offering price, less the underwriting discounts and commissions.

Morgan Stanley, Jefferies, Stifel and Guggenheim Securities are acting as joint book-running managers for the offering.

The offering is being made pursuant to a shelf registration statement on Form S-3 that was previously filed with the Securities and Exchange Commission (“SEC”) on March 5, 2024 and became automatically effective upon filing. This offering is being made only by means of a prospectus supplement and accompanying prospectus that form a part of the registration statement. A preliminary prospectus supplement relating to and describing the terms of the offering has been filed with the SEC and may be obtained for free by visiting the SEC’s website at www.sec.gov. A final prospectus supplement relating to the offering will be filed with the SEC. When available, copies of the final prospectus supplement and the accompanying prospectus may also be obtained by contacting: Morgan Stanley & Co. LLC, Attention: Prospectus Department, 180 Varick Street, 2nd Floor, New York, NY 10014, or by email at prospectus@morganstanley.com; Jefferies LLC, Attention: Equity Syndicate Prospectus Department, 520 Madison Avenue, New York, NY 10022, by telephone at (877) 821-7388, or by email at Prospectus_Department@Jefferies.com; Stifel, Nicolaus & Company, Incorporated, Attention: Prospectus Department, One Montgomery Street, Suite 3700, San Francisco, CA 94104, by telephone at (415) 364-2720 or by email at syndprospectus@stifel.com; or Guggenheim Securities, LLC, Attention: Equity Syndicate Department, 330 Madison Avenue, 8th Floor, New York, NY 10017, by telephone at (212) 518-9544, or by email at GSEquityProspectusDelivery@guggenheimpartners.com.   

This press release shall not constitute an offer to sell, or a solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About Dyne Therapeutics

Dyne Therapeutics is focused on delivering functional improvement for people living with genetically driven neuromuscular diseases. We are developing therapeutics that target muscle and the central nervous system (CNS) to address the root cause of disease. The company is advancing clinical programs for myotonic dystrophy type 1 (DM1) and Duchenne muscular dystrophy (DMD), and preclinical programs for facioscapulohumeral muscular dystrophy (FSHD) and Pompe disease. At Dyne, we are on a mission to deliver functional improvement for individuals, families and communities.

Forward-Looking Statements  

This press release contains forward-looking statements that involve substantial risks and uncertainties. All statements, other than statements of historical facts, contained in this press release, including statements relating to the anticipated closing date of the public offering, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “objective,” “ongoing,” “plan,” “predict,” “project,” “potential,” “should,” or “would,” or the negative of these terms, or other comparable terminology are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Dyne may not actually achieve the plans, intentions or expectations disclosed in these forward-looking statements, and you should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various important factors, including the risks and uncertainties related to the satisfaction of customary closing conditions for the public offering and other factors discussed in the “Risk Factors” section of the preliminary prospectus supplement filed with the SEC on December 8, 2025, as well as the risks and uncertainties identified in Dyne’s filings with the SEC, including Dyne’s most recent Form 10-Q and in subsequent filings Dyne may make with the SEC. In addition, the forward-looking statements included in this press release represent Dyne’s views as of the date of this press release. Dyne anticipates that subsequent events and developments will cause its views to change. However, while Dyne may elect to update these forward-looking statements at some point in the future, it specifically disclaims any obligation to do so. These forward-looking statements should not be relied upon as representing Dyne’s views as of any date subsequent to the date of this press release.

Contacts:
 
Investors

Mia Tobias
ir@dyne-tx.com
781-317-0353

Media

Stacy Nartker
snartker@dyne-tx.com
781-317-1938

FAQ

How many shares is Dyne (DYN) offering and at what price?

Dyne is offering 18,980,478 shares at $18.44 per share.

How much gross capital will Dyne (DYN) raise from the offering?

The offering is expected to generate $350.0 million in gross proceeds before fees.

When will the Dyne (DYN) offering close and is the date final?

The offering is expected to close on or about December 11, 2025, subject to customary closing conditions.

Will Dyne (DYN) grant an overallotment option and how large is it?

Yes, Dyne granted a 30-day option to underwriters to buy up to 2,847,071 additional shares.

Who are the joint book-running managers for Dyne's (DYN) offering?

Joint book-running managers are Morgan Stanley, Jefferies, Stifel and Guggenheim Securities.