Rallybio Sets 1-for-2 Reverse Split Ahead of Avenzo Merger

Rallybio Corporation (Nasdaq: RLYB) said on November 10, 2026 that it will effect a one-for-two reverse stock split of its issued and outstanding common stock, a move the company tied directly to its proposed merger with Avenzo Therapeutics. The split takes effect at 12:01 a.m. Eastern Time on November 20, 2026, and will cut Rallybio's issued and outstanding share count from approximately 5.6 million to roughly 2.8 million, before the merger closes. The company said its Board of Directors approved the ratio on November 8, 2026, with Avenzo's mutual agreement.

Context — why a reverse split now, ahead of the Avenzo merger?

The timing is the story. Rallybio is not using the split to fix a listing deficiency in isolation; it is doing it "prior to the anticipated completion of the merger contemplated by the Merger Agreement," the company said. The split is a housekeeping step that must clear before the combined entity can begin trading under a new identity.

Stockholders had already authorized the mechanics. At Rallybio's Annual Meeting of Stockholders on November 4, 2026, holders approved an amendment to the company's Amended and Restated Certificate of Incorporation permitting a reverse split at any ratio from one-for-two to one-for-nine, with the final figure left to Rallybio and Avenzo to settle jointly. The board and Avenzo landed at the low end of that authorized range.

The merger itself rests on an Agreement and Plan of Merger and Reorganization dated May 31, 2026, among Rallybio, Avenzo and Farmington Merger Sub, Inc., a wholly owned Rallybio subsidiary. Under that structure, Rallybio is the surviving vehicle absorbing Avenzo's pipeline.

After applicable Nasdaq approvals and the closing, Rallybio plans to rename itself Avenzo Therapeutics, Inc. and trade on the Nasdaq Capital Market under the symbol "AVZO" and a new CUSIP number, 053928 107. The company did not disclose the expected closing date of the merger, nor the terms of the transaction.

The macro backdrop for small-cap biotech is not the driver here. This is a corporate-action sequence — shareholder vote, board approval, split, ticker change — running on its own timetable, independent of rates or index levels.

Data — what the numbers show

The arithmetic is straightforward and worth stating precisely. Every two issued and outstanding shares of Rallybio common stock automatically combine into one share at the effective time. That takes the count from about 5.6 million to about 2.8 million. The authorized number of shares is unchanged, and par value stays at $0.0001 per share.

Item	Before split	After split
Issued and outstanding shares	~5.6 million	~2.8 million
Par value per share	$0.0001	$0.0001
Authorized shares	Unchanged	Unchanged
Trading symbol	RLYB	AVZO (post-merger)

The split applies uniformly across all holders and, by itself, does not change any stockholder's percentage interest in Rallybio's equity — with one narrow exception. Stockholders who would otherwise receive a fractional share get cash instead, equal to the fair market value of that fraction based on the closing price of Rallybio common stock on the split's effective date. No fractional shares will be issued.

Proportionate adjustments will be made to the number of shares underlying outstanding pre-funded warrants, equity awards and, where applicable, their exercise prices, and to the number of shares reserved under Rallybio's equity incentive plans, in each case per the terms of the applicable instruments.

Computershare Trust Company, N.A. is acting as exchange agent and transfer agent. Holders with shares in book-entry form need take no action; those holding physical certificates will receive instructions from Computershare on exchanging them for post-split book-entry shares and on fractional-share payments. Holders through a bank, broker or nominee will have positions adjusted by that intermediary.

Analysis — what it means for markets, sectors and tickers

The read-through for RLYB holders is mostly mechanical rather than directional. A one-for-two split doubles the per-share price while halving the count; market capitalization is unaffected by the split alone. What changes is the optics of the share price and the share count on the combined company's books once the ticker flips to AVZO.

The second-order effects sit with the pipeline, not the split. Avenzo is a clinical-stage oncology company whose assets include AVZO-021 and AVZO-023, described as novel, highly potent and selective inhibitors of CDK2 and CDK4 respectively. AVZO-021 is in a Phase 1/2 study as monotherapy in advanced solid tumors and in combination with fulvestrant in HR+/HER2- metastatic breast cancer. Both compounds are being tested in the Phase 1/2 ORION-1 study in HR+/HER2- metastatic breast cancer, where AVZO-023 is given with endocrine therapy, with or without AVZO-021.

Avenzo also lists two bispecific antibody-drug conjugates. AVZO-1418, an EGFR/HER3 bispecific ADC, is in the AVENTINE-1 Phase 1/2 study for advanced solid tumors, while AVZO-103, a Nectin4/TROP2 bispecific ADC, is in the BEACON-1 Phase 1/2 study for advanced solid tumors. These are early-stage programs, and the report gives no efficacy or safety data, no enrollment figures and no timelines.

The limitation to weigh: a reverse split is often read by the market as a signal of share-price weakness, and the company offers no share-price target, valuation or post-merger financials. Positioning here is event-driven — holders of record as of the effective date simply receive combined shares, and the stock's next real test comes when AVZO begins trading and the market prices Avenzo's clinical readouts.

Outlook — what to watch next

Three dates anchor the calendar, all supplied by the company. The reverse split becomes effective at 12:01 a.m. Eastern Time on November 20, 2026. The merger is expected to complete after that, subject to the conditions in the Merger Agreement. The ticker and name change to Avenzo Therapeutics, Inc. and "AVZO" follow the closing, contingent on applicable Nasdaq approvals.

Investors should also watch the CUSIP transition to 053928 107, which signals the corporate-action processing is complete, and any subsequent filings that disclose the combined company's share structure, board and leadership. The company did not disclose a merger closing date, so the sequence from split to ticker change remains the key variable.

Frequently Asked Questions

What does a one-for-two reverse stock split mean for Rallybio shareholders?

Every two shares held automatically become one. A holder of 200 shares ends with 100, and the per-share price adjusts proportionally. The split does not change any holder's percentage ownership, except where the combination produces a fractional share, in which case the holder receives cash equal to that fraction's fair market value based on the closing price on the effective date.

Why is Rallybio doing the reverse split before the Avenzo merger closes?

The company said the split is being effected in connection with the transactions contemplated by the Merger Agreement and is expected to become effective prior to the anticipated completion of the merger. Stockholders authorized a ratio range of one-for-two to one-for-nine on November 4, 2026, and the board, with Avenzo's agreement, chose the one-for-two end of that range.

What happens to Rallybio stock after the merger and ticker change?

Following applicable Nasdaq approvals and the closing, Rallybio plans to rename itself Avenzo Therapeutics, Inc. and trade on the Nasdaq Capital Market under the symbol "AVZO" with a new CUSIP number, 053928 107. The company did not disclose when the merger will close or the terms of the transaction, so the exact timing of the ticker change remains unconfirmed.

Bottom Line

Rallybio's one-for-two reverse split is a merger precondition, not a fix for its own balance sheet, and AVZO trading is the next checkpoint.

Disclaimer: This article is for informational purposes only and does not constitute investment advice. CFD trading carries high risk of capital loss.