📜 What This Document Is 🗳️

This document is a Definitive Proxy Statement (DEF 14A). Simply put, it is a massive, formal instruction manual that the company provides to its shareholders before an annual meeting. Its purpose is to inform you about what business will be conducted, who you are electing, and how you need to vote your shares.

👉 The primary goal of this document is to help shareholders vote at the 2026 Annual Meeting of Stockholders to approve director elections and other corporate matters. It also contains deep details on the company's executives and how they are paid.

🏢 BillionToOne, Inc. Overview 🔬

BillionToOne, Inc. is a company focused on the field of diagnostics. In simple terms, they are involved in molecular diagnostics, which means they analyze biological material (like DNA) to provide insights into health and disease.

👉 The company was co-founded and led by Oguzhan Atay, PhD, who has overseen the Company since its inception in 2016.

🗓️ The 2026 Annual Meeting Logistics 💻

The Annual Meeting of Stockholders is the formal gathering where shareholders vote on critical corporate decisions. For 2026, the meeting is scheduled for Wednesday, June 10, 2026, at 9:00 a.m. PDT.

👉 The meeting will be held virtually via a live audio webcast at www.virtualshareholdermeeting.com/BLLN2026. While the meeting is virtual, the company encourages all stockholders to vote as soon as possible, whether online, by telephone, or by mail.

• Record Date: You are entitled to vote if you were a stockholder of record as of the close of business on April 17, 2026.
• Voting Method: The company recommends using the internet to vote, and proxy materials can be accessed online at www.proxyvote.com.

🗳️ Key Votes for the Shareholders 🗳️

The main purpose of the meeting is to elect corporate leaders and approve essential corporate services. Shareholders will vote on two primary matters:

• Electing Directors: Shareholders will vote to elect two directors to serve as Class I directors until the 2029 Annual Meeting. The Board of Directors unanimously recommends voting FOR both nominees: Oguzhan Atay and Akshay Rai.
• Auditor Ratification: Shareholders must vote to ratify the appointment of PricewaterhouseCoopers LLP (PwC) as the independent registered public accounting firm for the year ending December 31, 2026.

👉 Voting Power: The company has different voting rules for its stock classes. Class A common stock is entitled to one vote per share, while Class B common stock is entitled to 15 votes per share.

👥 Board of Directors and Officers 👨‍💼

The company is led by a robust team of executives and board members with deep experience in biotechnology and finance.

• Board Experience: The full Board of Directors is overseen by risk management committees (Audit, Compensation, and the full Board), ensuring the company monitors areas like finance, legal issues, and cybersecurity.
• Executive Team Highlights:
  • Oguzhan Atay, PhD (CEO/Co-Founder & Board Chair): Leads the company, bringing experience from Princeton University and co-developing the molecular counting platform.
  • Ross Taylor (CFO): Brings three decades of financial leadership, having served as CFO for Codexis, Inc. and Abaxis, Inc.
  • Shan Riku Sakakibara (CPO): Has over 15 years of experience in launching and managing products, from software to precision diagnostics, and previously worked at Natera, Inc.
  • John Lister (CAO): Has deep background in the healthcare space, having worked for Dexcom, Inc. (a continuous glucose monitoring system producer) from 2008 to 2019.

💰 Executive Compensation Deep Dive 💵

The compensation structure is highly detailed and uses a "Pay for Performance" philosophy. This means that executive pay is designed to reward results, linking the executives' success directly to the company's growth.

• Core Philosophy: The Compensation Committee aims for a program that is market-competitive, and most importantly, links compensation to results that matter. The compensation is deliberately structured to overweight equity (stock) relative to cash.
• 2025 vs. 2024 Highlights (NEOs):
  • Oguzhan Atay, PhD (CEO): His total compensation in 2025 was $19,684,903, significantly up from $371,064 in 2024.
  • David Tsao, PhD (CTO): Total compensation in 2025 was $10,044,036, up from $367,653 in 2024.
  • John Lister (CAO): Total compensation in 2025 was $3,361,110. This figure was also pro-rated because he commenced his role on July 7, 2025.
• Key Components:
  • Base Salary: For 2025, salaries for the NEOs increased and were aligned with competitive market levels following the IPO.
  • Annual Incentive Compensation (Bonus): For 2025, the NEOs earned percentages of their target bonus. For example, Dr. Atay earned $136,001 (124% of target).
  • Equity Compensation: This is the large, long-term incentive component. Grants vest over time (e.g., 4 or 6 years) and encourage executives to keep working at the company.

🛡️ Governance, Risk, and Legal Protection 🚧

The company has established structures to manage potential risks and protect its leadership.

• Board Oversight: The Board oversees major risk areas, including operations, finance, legal, regulatory, and cybersecurity. The Audit Committee oversees financial reporting risk, while the Compensation Committee ensures compensation doesn't encourage excessive risk-taking.
• Severance Plan: The Board approved the Executive Severance Plan, which provides specific protections if an executive is terminated.
  • Tier 1 Participants (Dr. Atay): If involuntarily terminated (and not a Change in Control), eligibility includes 12 months of base salary continuation.
  • Tier 2 Participants (Dr. Tsao and Mr. Lister): If involuntarily terminated, eligibility includes 9 months of base salary continuation.

✍️ Stockholder Proposals and Administration 📣

Shareholders have specific rules for proposing items for future consideration.

• Proposals for 2027: Any stockholder wishing to propose actions or nominate directors for the 2027 annual meeting must submit proposals in writing to the Secretary by no later than December 21, 2026.
• Notice of Materials: The company mailed a Notice of Internet Availability of Proxy Materials on or about April 21, 2026, which provided details on how to access and vote proxy materials.
• Principal Contact: All written correspondence regarding shareholder communication should be sent to the principal executive offices at 1035 O’Brien Drive, Menlo Park, CA 94025.

🧠 The Analogy 🏫

Voting at an Annual Meeting is like deciding who gets to run the school principal's office next year. The proxy statement is the detailed rulebook and candidate biography packet. It doesn't just tell you who is running (the nominees); it also tells you how much the current leaders are paid, what rules they have to follow (the governance), and what happens if they get fired (severance). Every section is designed to give you enough information to vote with total knowledge.

🧩 Final Takeaway 💡

This proxy statement is a massive resource for shareholders, detailing everything from the rules of corporate governance and director nominations to the complex financials of executive pay. The key dates to remember are the Record Date (April 17, 2026) for voting eligibility and the Annual Meeting (June 10, 2026) when the votes will take place.