Onconetix, Inc. (NASDAQ: ONCO) has filed an S-1 registration statement covering the resale of up to 100,000,000 shares of common stock tied to a $25 million equity line of credit (ELOC) with Keystone Capital Partners. The registered share count is approximately 27 times the company's current 3,691,492 shares outstanding, representing roughly 96.4% of the post-issuance float if fully drawn.

The ELOC allows Onconetix to direct Keystone to purchase shares at a 10% discount to a short-window VWAP measure. At the filing's assumed offering price of $0.1375 per share, full utilization of the facility would require issuing the entirety of the 100 million registered shares. Because the pricing is variable and tied to prevailing market levels, the effective share count issued under the facility fluctuates inversely with the stock price — a lower price means more shares must be issued for the same dollar amount of capital.

Two Reverse Splits in Two Months

The filing discloses two reverse stock splits executed in rapid succession during 2026: a 1-for-5 reverse split on March 25, followed by a 1-for-10 reverse split on May 21. Together, these reduced the pre-split share count by a factor of 50. Despite this consolidation, the current share price remains in the sub-dollar range, which is the basis for the large number of shares being registered.

Variable-Priced Preferred Overhang

Onconetix's capital structure includes multiple series of preferred stock — Series C, D, and E — each carrying provisions that compound dilution risk. These series feature full-ratchet anti-dilution protection, meaning any issuance of common stock below their conversion price resets the conversion ratio downward to match, increasing the number of common shares into which they convert. The preferred series also carry 15% default dividend rates and floor prices that have been repeatedly adjusted lower in connection with the reverse splits.

The interaction between the ELOC and these preferred instruments is structurally significant. As discounted ELOC shares enter the market and potentially pressure the common stock price, the full-ratchet provisions on the preferred series can trigger conversion-price resets, which in turn generate additional dilution — a self-reinforcing cycle sometimes referred to in capital-structure analysis as a "death spiral" mechanic.

Facility Mechanics

The company controls the timing and size of individual drawdowns, meaning dilution is not immediate but contingent on management's decision to access the facility. However, the S-1 registration of the full 100 million shares signals the company's intent to have the capacity available. With approximately $6.5 million in cash and an accumulated deficit of $135.4 million, the ELOC appears positioned as a primary near-term funding mechanism.

The filing's dilution table illustrates the math plainly: at $0.1375 per share, existing shareholders would see their proportional ownership reduced from 100% to approximately 3.6% if the full facility is utilized, before accounting for any additional dilution from preferred conversions or other outstanding instruments.