Corporate Action (Form 8-K)

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.