Company: BLLN
Filing Date: 2025-10-07
Form Type: S-1
Source: 0001193125-25-233697
Chunk: 27

Company: BillionToOne, Inc.
Filing Date: 2025-10-07
Form: S-1
Chunk 27
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-molecule precision and sensitivity, capturing the key disease-causing molecular signatures in cfDNA; and second, our response monitoring assay provides an objective measurement of how a patient is responding to a therapy. AI has recently unlocked widespread access to and analysis of multimodal patient clinical history data. This powerful combination positions us to harness AI for identifying distinct patient subgroups based on their specific biomarker profiles and for predicting how each subgroup will respond to different therapeutic approaches. By mapping these response patterns with extraordinary granularity, we believe we will be able to deliver personalized treatment recommendations based on each person’s unique biology that maximize efficacy while minimizing adverse effects — moving precision medicine from aspiration to clinical reality.

| 20 |     | Both MRD and early-detection assays are designed to detect minute amounts of cancer DNA in blood (e.g., at levels of 0.01% or even lower). Given the trade off between specificity and sensitivity (LOD), this higher                             
 specificity can be, in principle, achieved by changing the calling threshold. As a part of our five-year strategic plan, we have included the necessary R&D funding for development of an early detection test that builds upon our earlier work. |

| 21 |     | See “Management’s discussion and analysis of financial condition and results of operations—Key factors affecting our results of operations and performance” for more information regarding how 
 these total addressable markets are calculated, including material assumptions.                                                                                                                |

9

While our AI-enabledvision represents the future of our platform, our commercial success today demonstrates the fundamental value of our existing products. Our existing products in prenatal and oncology have already demonstrated strong growth from zero to $266.3 million annualized revenue run-rate(ARR) in five years as of June 30, 2025. As we expand into new and larger markets, we believe that our foundational smNGS platform will position us to become a generational healthcare company. Our growth strategy We are driving and leading a paradigm shift within precision diagnostics. Our vision is to leverage our novel smNGS platform to develop ultrasensitive diagnostic tests that enable personalized solutions and enhance patient outcomes. Our growth strategy to achieve this goal includes the following elements:

| • |     | Drive increased adoption of our existing products in the prenatal and oncology markets. |

| • |     | Build beyond our extensive library of clinical evidence to support favorable coverage and reimbursement. |

| • |     | Utilize our smNGS platform and R&D capabilities to efficiently expand and improve our portfolio of category-defining 
 molecular