Form 4: Day One Bio CCO Reports Stock Transactions & RSU Vesting

Day One Biopharmaceuticals' Chief Commercial Officer, Lauren Merendino, reported recent stock acquisitions from RSU vesting and an employee stock purchase plan, alongside a sale to cover tax liabilities.

Summary

• Lauren Merendino, Chief Commercial Officer of Day One Biopharmaceuticals, Inc. (DAWN), reported multiple transactions involving the company's common stock and Restricted Stock Units (RSUs).
• On November 15, 2025, Merendino acquired a total of 10,536 shares of Common Stock through the settlement of RSUs (3,162, 3,687, and 3,687 shares).
• Following these acquisitions, Merendino's direct beneficial ownership of Common Stock increased to 54,535 shares.
• On November 17, 2025, Merendino sold 3,726 shares of Common Stock at a weighted average price of $8.9147 per share.
• The sale was explicitly stated to be for the sole purpose of covering tax liability related to the settlement of RSUs.
• After the sale, Merendino's direct beneficial ownership of Common Stock was 50,809 shares.
• The reported beneficial ownership also includes 2,068 shares of Common Stock acquired on May 15, 2025, through the Issuer's employee stock purchase plan.
• Merendino holds remaining derivative securities in the form of RSUs, totaling 44,252 units after the reported conversions.

Sentiment

Score: 5

Explanation: The filing is a routine insider transaction report, reflecting standard compensation and tax-related sales, thus indicating a neutral sentiment.

Positives

• The Chief Commercial Officer's acquisition of shares through RSU vesting and an employee stock purchase plan indicates continued alignment of management interests with shareholders.
• RSU vesting represents a form of compensation, reflecting the executive's ongoing service to the company.

Negatives

• A sale of shares by an insider, even for tax purposes, reduces their direct ownership stake in the company.

Future Outlook

Remaining portions of RSU awards are scheduled to vest in future quarterly installments. One award's remaining 3/4 will vest in 12 substantially equal quarterly installments on November 15, February 15, May 15, and August 15. Another RSU award will vest in 1/16th quarterly installments on February 15, May 15, August 15, and November 15.

Industry Context

This filing is a routine insider transaction report (Form 4) and does not provide information directly related to broader industry trends or competitive landscape. It reflects an executive's compensation and personal financial management within the company's existing equity plans.

Stakeholder Impact

• Shareholders: Provides transparency regarding executive stock ownership and transactions, which is standard for publicly traded companies.
• Employees: The mention of an employee stock purchase plan (ESPP) highlights a benefit available to employees, potentially impacting morale and retention.

Next Steps

• Continued vesting of remaining Restricted Stock Units (RSUs) on a quarterly basis (February 15, May 15, August 15, November 15) as per the established vesting schedules, subject to the Reporting Person's continued service.

Key Dates

Keywords

Day One Biopharmaceuticals, DAWN, Lauren Merendino, Chief Commercial Officer, Form 4, Insider Trading, Restricted Stock Units, RSU Vesting, Common Stock, Employee Stock Purchase Plan, Tax Liability Sale