MACKAY MARTIN 4

What Happened Martin Mackay, a director of Rallybio Corp (RLYB), was granted a derivative award (an option) to acquire 18,055 shares at an exercise price of $3.60 per share, with a reported aggregate value of $64,998. The award was issued in lieu of $65,000 in director retainer fees under the company's 2021 Equity Incentive Plan. This is an equity grant (not an open-market purchase or sale).

Key Details

• Transaction date: 2026-02-18; Filing date: 2026-02-20 (filed two days after the transaction).
• Grant: option covering 18,055 shares, exercise price $3.60, implied value $64,998 (derivative award).
• Vesting: vests in 11 equal installments, each on the last day of each remaining month of calendar year 2026 (per footnote).
• Issued under: Rallybio 2021 Equity Incentive Plan, in lieu of $65,000 retainer fees (per footnote).
• Shares owned after transaction: not disclosed in the provided filing excerpt.
• Timeliness: Filing appears timely (filed two business days after the transaction), not noted as late.

Context This was an option grant (derivative award) to a director rather than an open-market buy or sale. Options vest monthly per the stated schedule; they are not exercised or sold at grant, so this transaction does not by itself indicate immediate buying or selling of stock. Grants issued in lieu of cash compensation are a routine form of director pay and should be interpreted as compensation rather than a direct bullish or bearish trade by the insider.