Onconetix, Inc. filed a Form 8-K on October 26, 2026, disclosing that its Board of Directors approved a second 1-for-10 reverse stock split of its common stock, scheduled to take effect at 12:01 a.m. Eastern Time on November 6, 2026.

Key Highlights

  • Second reverse split approved: The Board determined on October 22, 2026, to effect a one-for-ten (1:10) reverse stock split of the company's common stock.
  • Aggregate ratio reaches 1:100: Combined with the prior one-for-ten split effective May 21, 2026, the total aggregate reverse stock split ratio will be one-for-one hundred (1:100).
  • Effective date: The reverse stock split is expected to become effective at 12:01 a.m. Eastern Time on November 6, 2026, with split-adjusted trading on NASDAQ beginning that same morning.
  • Share count reduction: The reverse stock split is expected to reduce outstanding shares from approximately 5.9 million to approximately 589,000 shares.
  • New CUSIP assigned: The common stock will trade under the existing symbol ONCO with a new CUSIP number, 68237Q500.
  • No fractional shares: Stockholders entitled to fractional shares will instead receive a cash payment equal to the fraction multiplied by the closing sale price on the trading day immediately preceding the effective time, as adjusted to reflect the reverse stock split.

Onconetix Board Completes Full 1:100 Split Authorization

According to the filing, Onconetix, Inc. (NASDAQ:ONCO), a Delaware-incorporated company headquartered in Cincinnati, Ohio, is a publicly traded emerging growth company. The Board's October 22, 2026, action draws on stockholder authorization that was granted at a special meeting held on April 30, 2026, at which stockholders approved discretionary authority for reverse stock splits at ratios ranging from one-for-two (1:2) to one-for-ten (1:10), subject to an aggregate cap of one-for-one hundred (1:100).

The filing reports that the company previously exercised a portion of that authority when it effected a one-for-ten (1:10) reverse stock split effective May 21, 2026. The current action represents the second and final use of that authorization, and the two splits together reach the maximum aggregate ratio of 1:100 permitted under the stockholder-approved proposal, according to the disclosure.

The company disclosed that a Certificate of Amendment to its Amended and Restated Certificate of Incorporation is expected to be filed with the Delaware Secretary of State on November 5, 2026. At the effective time, every ten shares of issued and outstanding common stock will automatically be combined into one share, with no corresponding reduction in authorized shares and no change in par value of $0.00001 per share. Proportional adjustments will apply to outstanding equity awards, convertible preferred stock, and warrants, including their applicable exercise or conversion prices, as the filing states.

What Was Disclosed

Onconetix disclosed a Board-approved one-for-ten reverse stock split to take effect November 6, 2026, completing the full 1:100 aggregate split authorized by stockholders in April 2026, and reducing outstanding shares from approximately 5.9 million to approximately 589,000.