[8-K] ATOSSA THERAPEUTICS, INC. Reports Material Event

Rhea-AI Filing Summary

Atossa Therapeutics, Inc. is implementing a 1-for-15 reverse stock split of its common stock, effective at 12:01 a.m. Eastern Time on February 2, 2026. At that time, each 15 shares of common stock will automatically be combined into one share, and the stock is expected to begin trading on a split-adjusted basis the same day under a new CUSIP, while keeping the ATOS ticker and the $0.18 par value per share.

No fractional shares will be issued; instead, stockholders will receive cash equal to the fractional share multiplied by the closing price of the stock on January 30, 2026, adjusted for the split. The company will make proportional adjustments to outstanding equity awards, plan share reserves, and the conversion terms of its Series B Convertible Preferred Stock. The reverse split was enabled by stockholder approval of an amendment allowing a reverse split in a range of 5:1 to 20:1, with 33,724,885 votes for, 27,888,393 against and 130,938 abstentions, out of 129,171,424 shares entitled to vote as of December 19, 2025.

Insights

Equity structure and corporate actions analyst

Atossa is executing a 1-for-15 reverse split to consolidate its share count while keeping its Nasdaq listing and par value unchanged.

The company’s board approved a reverse stock split at a 15:1 ratio, effective on February 2, 2026, after stockholders authorized a split range of 5:1 to 20:1. Each 15 existing shares of common stock will become one share, which typically reduces the number of shares outstanding and increases the trading price per share mechanically, without changing overall market value.

No fractional shares will be created; holders instead receive cash based on the closing price on January 30, 2026, multiplied by their fractional entitlement. The company will also adjust outstanding equity awards, share reserves under its equity plans, and the conversion terms of its Series B Convertible Preferred Stock in line with the 15:1 ratio, preserving economic equivalence across its capital structure.

As context, 129,171,424 shares of common stock were entitled to vote at the special meeting as of December 19, 2025, and the reverse split authorization passed with 33,724,885 votes in favor and 27,888,393 against. Future filings may provide updated post-split share counts and any resulting effects on equity compensation and preferred stock conversions.

8-K Event Classification

4 items: 3.03, 5.03, 5.07, 9.01

4 items

Item 3.03 Material Modification to Rights of Security Holders Securities

A change was made that materially affects the rights of existing shareholders (e.g., dividend rights, voting rights).

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year Governance

The company amended its charter documents, bylaws, or changed its fiscal year.

Item 5.07 Submission of Matters to a Vote of Security Holders Governance

Results of a shareholder vote on proposals at an annual or special meeting.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Understanding 8-K Material Events →

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 20, 2026

Atossa Therapeutics, Inc.

(Exact name of Registrant as Specified in Its Charter)

Delaware			001-35610	26-4753208
(State or Other Jurisdiction of Incorporation)			(Commission File Number)	(IRS Employer Identification No.)
1448 NW Market Street, Suite 500
Seattle, Washington				98107
(Address of Principal Executive Offices)				(Zip Code)

Registrant’s Telephone Number, Including Area Code: (206) 588-0256

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check th e appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock, $0.18 par value		ATOS		The Nasdaq Capital Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐
 

Atossa Therapeutics, Inc. (the “Company”) held a Special Meeting of Stockholders (the “Special Meeting”) on January 20, 2026 at 9:00 a.m. Pacific Time.

Item 3.03. Material Modification to Rights of Security Holders.

Following the Special Meeting, the Company’s Board of Directors approved a reverse stock split (the “Reverse Stock Split”) of the Company’s common stock, par value $0.18 per share (the “Common Stock”), at a ratio of 15:1 (the “Reverse Stock Split Ratio”) with an effective time of 12:01 a.m. Eastern Time on February 2, 2026 (the “Effective Time”). To effect the Reverse Stock Split, the Company filed an amendment to its Amended and Restated Certificate of Incorporation, as amended (the “Certificate of Incorporation”), with the Secretary of State of the State of Delaware (the “Amendment”).

The Common Stock is expected to commence trading on a split-adjusted basis at the open of trading on February 2, 2026, at which time the Common Stock will be represented by a new CUSIP number (04962H704). The Common Stock will continue to trade on the Nasdaq Stock Market under the symbol “ATOS.”

As of the Effective Time, each 15 shares of Common Stock outstanding will be combined, automatically and without any action on the part of the Company or its stockholders, into one new share of Common Stock. No fractional shares of Common Stock will be issued as a result of the Reverse Stock Split. In lieu of any fractional shares to which a stockholder of record would otherwise be entitled, the Company will pay cash (without interest and subject to withholding taxes, as applicable) equal to such fraction multiplied by the closing price of the Common Stock on the Nasdaq Stock Market on January 30, 2026 (as adjusted in good faith by the Company to account for the Reverse Stock Split Ratio). The par value per share of the Common Stock will remain unchanged.

In addition, effective as of the Effective Time and based on the Reverse Stock Split Ratio, proportionate adjustments will be made (i) in accordance with the terms of the Company’s equity plans, to the number of shares subject to outstanding equity awards, the per share exercise price, if any, with respect to those awards and the number of shares of Common Stock reserved for future issuance under such plans, and (ii) in accordance with the Certificate of Designation of Preferences, Rights and Limitation of the Series B Convertible Preferred Stock (the “Preferred Stock”), to the conversion price of the Preferred Stock and the number of shares of Common Stock reserved for issuance pursuant to the Preferred Stock.

The foregoing description of the Amendment does not purport to be complete and is subject to and qualified in its entirety by reference to the Amendment, a copy of which is attached hereto as Exhibit 3.1, and is incorporated herein by reference.

Item 5.03. Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

The information set forth in Item 3.03 of this Current Report on Form 8-K is incorporated by reference into this Item 5.03.

Item 5.07. Submission of Matters to a Vote of Security Holders.

As of the close of business on December 19, 2025, the record date for the Special Meeting, there were 129,171,424 shares of Common Stock entitled to vote at the meeting. At the Special Meeting, stockholders voted on and approved an amendment to the Certificate of Incorporation to effect a reverse stock split of the Common Stock at a reverse stock split ratio ranging from 5:1 to 20:1, inclusive, by the following votes:

Votes For	Votes Against	Abstentions	Broker Non-Votes
33,724,885	27,888,393	130,938	0

Item 9.01 Financial Statements and Exhibits

(d) Exhibits

Exhibit Number		Description of Exhibit
3.1		Certificate of Amendment to the Amended and Restated Certificate of Incorporation of Atossa Therapeutics, Inc.
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

			Atossa Therapeutics, Inc.
Date:	January 26, 2026	By:	/s/ Mark J. Daniel
			Mark J. Daniel Chief Financial Officer (Principal Financial and Accounting Officer)

FAQ

What reverse stock split did Atossa Therapeutics (ATOS) approve?

Atossa Therapeutics approved and is implementing a 1-for-15 reverse stock split of its common stock. Each 15 shares outstanding will be automatically combined into one new share.

When does the Atossa Therapeutics (ATOS) reverse stock split take effect?

The reverse stock split becomes effective at 12:01 a.m. Eastern Time on February 2, 2026, and the common stock is expected to begin trading on a split-adjusted basis at the open of trading that same day.

Will Atossa Therapeutics (ATOS) change its ticker or exchange after the reverse split?

No. After the reverse split, Atossa’s common stock will continue to trade on The Nasdaq Capital Market under the symbol "ATOS", but it will have a new CUSIP number (04962H704).

How will fractional shares be handled in the Atossa Therapeutics reverse split?

No fractional shares will be issued. Instead, stockholders will receive cash in lieu of fractional shares, equal to the fraction multiplied by the closing price of the common stock on January 30, 2026, as adjusted to reflect the 15:1 split.

How does the reverse split affect Atossa Therapeutics equity awards and preferred stock?

Effective with the split, the company will make proportionate adjustments to (i) the number of shares and exercise prices for outstanding equity awards and the number of shares reserved under its equity plans, and (ii) the conversion price and reserved shares related to the Series B Convertible Preferred Stock.

How did Atossa Therapeutics stockholders vote on the reverse split authorization?

Stockholders approved an amendment allowing a reverse split ratio between 5:1 and 20:1 with 33,724,885 votes for, 27,888,393 against, and 130,938 abstentions, out of 129,171,424 shares entitled to vote as of December 19, 2025.