aTyr Pharma, Inc. filed a Form 8-K on October 27, 2026, disclosing that it filed a Certificate of Amendment with the State of Delaware to effect a one-for-forty reverse stock split of its common stock, effective at 5:00 p.m. Eastern Time on October 28, 2026.

Key Highlights

  • Split ratio: Every 40 shares of common stock will be automatically combined into 1 share.
  • Share count reduction: Shares outstanding will decrease from approximately 100.5 million to approximately 2.5 million.
  • Authorized shares unchanged: The authorized common stock will remain 340,000,000 shares, with no change in par value per share.
  • Effective date: The Amendment becomes effective at 5:00 p.m. Eastern Time on October 28, 2026, with split-adjusted trading on the Nasdaq Capital Market beginning October 29, 2026.
  • Stockholder and board approval: Both were obtained on October 16, 2026, at a Special Meeting of Stockholders and by the board of directors, respectively.
  • New CUSIP: The new CUSIP number for the common stock following the reverse stock split is 002120301.
  • Fractional shares: No fractional shares will be issued; stockholders otherwise entitled to a fractional share will receive rounding up to a whole share.

aTyr Pharma Files Delaware Amendment to Complete 1-for-40 Reverse Split

According to the filing, aTyr Pharma, Inc. (NASDAQ:ATYR) filed a Certificate of Amendment to its Restated Certificate of Incorporation with the Secretary of State of the State of Delaware on October 27, 2026. The Amendment effects a one-for-forty (1-for-40) reverse stock split of the company's outstanding common stock and becomes effective at 5:00 p.m. Eastern Time on October 28, 2026. The company's common stock will continue trading under the ticker symbol "ATYR" on The Nasdaq Capital Market on a split-adjusted basis when the market opens on October 29, 2026.

The filing states that the specific 1-for-40 ratio was approved by the company's board of directors on October 16, 2026, following stockholder approval of a series of alternate reverse stock split ratios at a Special Meeting of Stockholders held the same day. As a result of the reverse stock split, the filing reports that outstanding shares will be reduced from approximately 100.5 million to approximately 2.5 million, while the total authorized shares of common stock will remain at 340,000,000 with no change in par value per share.

The filing further discloses that proportionate adjustments will be made to the per share exercise price and the number of shares issuable upon exercise or vesting of all outstanding stock options, restricted stock units, and warrants. In the case of stock options and warrants, the exercise price will increase proportionately. The number of shares reserved for issuance under the company's equity compensation plans will also be reduced proportionately. The reverse stock split will affect all stockholders proportionately and will not affect any stockholder's percentage ownership, according to the filing, except to the extent a stockholder would otherwise own only a fractional share.

What Was Disclosed

aTyr Pharma disclosed the filing of a Certificate of Amendment effecting a 1-for-40 reverse stock split, effective October 28, 2026, reducing outstanding shares from approximately 100.5 million to approximately 2.5 million, with split-adjusted trading beginning October 29, 2026 under the same ticker symbol.