Here are 1-2 brief analogies for BillionToOne (BLLN):

• Think of it as Natera (NTRA), but offering a more comprehensive non-invasive prenatal genetic test.
• Imagine a company like Guardant Health (GH), but one that also specializes in advanced non-invasive prenatal genetic testing.

• Unity Screen (or Unity Fetal Risk Screen): A non-invasive prenatal test that screens for common chromosomal abnormalities and recessive genetic conditions from a single maternal blood sample.
• Northstar Select: A personalized liquid biopsy test designed to detect and monitor minimal residual disease (MRD) in cancer patients after treatment.

BillionToOne (BLLN) primarily sells its molecular diagnostic products and services to other companies and institutions, rather than directly to individuals. Based on their public filings, the company's major customers fall into the following categories:

• Clinical Laboratories: These include reference laboratories and other diagnostic labs that utilize BillionToOne's UNITY Screen for prenatal testing or QUANTISON platform for oncology applications.
• Hospitals and Health Systems: Large medical centers and integrated health networks that incorporate BillionToOne's tests into their diagnostic offerings for patient care.
• Academic Research Institutions: Universities and research-focused hospitals that use BillionToOne's technology for research and development purposes, particularly with the QUANTISON platform.

As of their latest public filings, BillionToOne has not disclosed specific names of major customers that individually account for a significant portion of their revenue. Therefore, specific customer company names and their symbols are not publicly available.

• Illumina, Inc. (ILMN)

Oguzhan Atay, Chief Executive Officer and Chair of the Board

Oguzhan Atay is a Co-Founder, Chief Executive Officer, and Board Chair of BillionToOne. He co-founded the company with David Tsao and has led it since its inception, raising over $200 million in funding. He also played a key role in developing BillionToOne's proprietary molecular counting platform. Prior to BillionToOne, he founded one other company. He holds a PhD in Systems Biology from Stanford University and a bachelor's degree in molecular biology from Princeton.

Ross Taylor, Chief Financial Officer

Ross Taylor joined BillionToOne as Chief Financial Officer in January 2024, bringing 30 years of financial leadership experience. He previously served as Chief Financial Officer for Codexis, Inc. from 2019 to 2023. From August 2015 to July 2018, he was the Chief Financial Officer of Abaxis, Inc., which was subsequently acquired by Zoetis. Taylor also spent 20 years as an equity research analyst on Wall Street, covering life sciences, healthcare, and diagnostics for firms such as CL King & Associates, UBS, Smith Barney, and CJ Lawrence.

David Tsao, President, Chief Technology Officer and Director

David Tsao is a Co-Founder and Chief Technology Officer (CTO) of BillionToOne. He is the original inventor of the company's molecular counting platform and oversees all technology developments. Tsao believes in applying engineering principles to biology to transform medicine. He holds a PhD in bioengineering from Rice University and a bachelor's degree in physics from Princeton University. In addition to his role at BillionToOne, he has founded one other company and is an angel investor in three startups.

John Lister, Chief Administrative Officer

John Lister serves as BillionToOne's Chief Administrative Officer, leading the People, Legal, IT, and RA/QA teams. Before joining BillionToOne, he held various leadership positions at Dexcom, a continuous glucose monitoring company, where he was part of the executive leadership team and led the Legal, People, and International teams. During his time at Dexcom, the company grew significantly in both employees and revenue. Most recently, Lister was the Chief Operating Officer for Tidepool, a diabetes software startup.

Shan Riku, Chief Product Officer

Shan Riku is the Chief Product Officer at BillionToOne. She holds an MBA.

1. Product/Service Concentration and Intense Competition: A substantial portion of BillionToOne's revenue is currently generated from its UNITY prenatal testing platform. While the company is expanding into the oncology diagnostics market with its Northstar products, this sector is highly competitive with numerous existing players and new entrants. Significant dependence on a few core products and the challenges of gaining market share in a crowded and competitive oncology diagnostics space pose a key risk to the company's financial stability and growth.
2. Regulatory Scrutiny and Reimbursement Challenges: The molecular diagnostics industry, in which BillionToOne operates, is subject to extensive regulation. Changes in FDA requirements, payer guidelines, or shifts in insurance reimbursement policies could introduce delays in product development and commercialization, increase operational costs, or negatively impact the company's revenue streams.
3. Path to Sustained Profitability and High Valuation: Despite rapid revenue growth, BillionToOne has only recently achieved a positive GAAP operating margin in Q3 2025. The company's valuation has been described as speculative due to historically negative earnings and a high price-to-sales (P/S) ratio. Sustaining profitability while simultaneously funding continued rapid expansion into new and competitive markets, particularly oncology, presents a significant ongoing challenge for the business.

BillionToOne (BLLN) operates in the molecular diagnostics space, primarily offering non-invasive prenatal tests and oncology liquid biopsy tests. The company estimates a significant addressable market for its products and pipeline.

The main products and their addressable markets are as follows:

• Prenatal Screening Tests (UNITY Complete®, UNITY Screen™, UNITY Fetal Risk Screen™): BillionToOne's non-invasive prenatal tests, such as UNITY Complete®, assess fetal risk for aneuploidies, recessive conditions, and fetal antigens from a maternal blood sample. The company has captured an estimated 15% market share in the U.S. prenatal testing market. The broader prenatal testing market is estimated at approximately $5 billion.
• Oncology Liquid Biopsy Tests (Northstar Select®, Northstar Response®): BillionToOne offers pan-cancer liquid biopsy tests, including Northstar Select® for guiding therapy selection and Northstar Response® for monitoring treatment response. The addressable market for oncology liquid biopsy is estimated by BillionToOne to be over $20 billion or over $50 billion.
  More broadly, the global liquid biopsy market is estimated at approximately $7.05 billion in 2025 and is projected to grow to about $22.69 billion by 2034. The U.S. liquid biopsy market size was estimated at $2.40 billion in 2025 and is expected to reach around $7.32 billion by 2034. The global market for cancer liquid biopsy products is projected to reach $33.5 billion by 2033. Additionally, BillionToOne is developing a tumor-naive minimal residual disease test, targeting an additional $30 billion market opportunity.
• Combined Addressable Market: BillionToOne estimates the total addressable market for its prenatal screening tests and oncology assays to be a global opportunity of $100 billion.

BillionToOne (BLLN) is expected to drive future revenue growth over the next 2-3 years through several key strategies:

• Continued growth in prenatal testing business: The company's UNITY Screen prenatal test has captured an estimated 15% market share in the U.S. and is noted for its strong growth momentum. The company has achieved robust growth in this segment with a smaller sales force compared to its largest competitor, indicating product differentiation and technological strength.
• Expansion and adoption in the oncology liquid biopsy market: BillionToOne is actively accelerating its presence in the oncology liquid biopsy market, which is projected to be worth over $20 billion. Its Northstar Select and Northstar Response assays, launched in 2023, have shown significant commercial progress and superior detection capabilities, having exceeded 3,000 ordered tests in Q4 2024.
• Launch of new diagnostic products, including a tumor-naive minimal residual disease (MRD) test: The company is developing a tumor-naive minimal residual disease test, which targets an additional market opportunity estimated at $30 billion. This pipeline of new products is anticipated to open new revenue streams.
• Leveraging proprietary technology for superior diagnostic capabilities: BillionToOne's patented Quantitative Counting Templates (QCT) molecular counting platform allows for ultra-sensitive, single-molecule DNA quantification. This technological advantage enables their tests, like Northstar Select, to identify significantly more genetic variants than competing solutions, driving adoption due to enhanced accuracy.
• Improved operational efficiency and profitability: While not a direct revenue driver, the company has shown improvements in gross margin, rising from 24% in 2023 to 53% in 2024 and reaching 65% in the first half of 2025. This increase in efficiency and narrowing net losses (to $4.2 million in H1 2025 from $82.7 million in 2023) indicates a stronger financial position to reinvest in growth initiatives and product development. The coming down of costs per test is a factor driving the company towards profitability.

Share Repurchases

• As of November 3, 2025, BillionToOne's buyback yield was 0.00%, indicating no recent share repurchases.

Share Issuance

• BillionToOne completed an upsized initial public offering (IPO) of 4,551,100 shares of Class A common stock at $60.00 per share, raising approximately $273.1 million in gross proceeds.
• The underwriters fully exercised their option to purchase an additional 682,665 shares, increasing the total gross proceeds from the IPO to approximately $314.0 million.

Inbound Investments

• Prior to its IPO, BillionToOne raised a total of $389 million across 10 funding rounds.
• The company's largest funding round was a $130 million Series D in June 2024, led by Premji Invest.
• As of June 30, 2025, BillionToOne had booked fair market value investments totaling $456 million from various investors including Hummingbird Ventures, Libertus Capital, Pamir Gelenbe, Premji Invest, Adams Street, and Neotribe Ventures.

Capital Expenditures

• BillionToOne's recent capital spending history indicates continued expenditures despite generating negative operating cash flow.
• Proceeds from the IPO are intended for working capital, research and development, technology development, and general corporate purposes, which would encompass capital expenditures.
• The primary focus of capital expenditures aligns with expanding the company's test menu, automation, and AI integration to enhance operational efficiency and product innovation.