Rapid oncology adoption at BillionToOne

Fast early test volume in oncology usually means the company has cleared the two real bottlenecks in liquid biopsy, getting doctors to order the test and getting payers to reimburse it. BillionToOne launched its oncology products in 2022, reached roughly 3,000 oncology tests in Q4 2024, and paired that ramp with Medicare coverage for Northstar Select in February 2025. That points to demand that is operational, not just scientific, because oncologists only switch ordering behavior when a test changes treatment decisions and fits clinic workflow.1 2 3 4

• This is a harder market to break into than prenatal testing. Oncology testing needs stronger validation, tighter oversight, and more evidence before doctors trust results for drug selection or monitoring. BillionToOne also built around this with a planned 220,000 square foot Austin facility, which suggests demand strong enough to justify scaling lab capacity.1 2
• The product story is concrete. Northstar Select is used to find mutations from a blood draw that can steer therapy choice, while Northstar Response is used to track whether treatment is working over time. In head to head validation, Northstar Select found 51% more clinically actionable alterations and produced fewer null reports, which gives sales reps a simple reason for doctors to try it.3 4 5
• The competitive benchmark matters. Guardant Health and Foundation Medicine are established in broad genomic profiling, while Natera has built traction in MRD monitoring. BillionToOne is not winning by creating a new category, it is taking share in an existing one by claiming better sensitivity and easier clinical use, which is the clearest form of product market fit in diagnostics.1 5 6

The next step is turning early adoption into a full oncology franchise. If BillionToOne keeps expanding reimbursement, adds products like tissue of origin and MRD, and proves better outcomes in more studies, oncology can evolve from a promising second line into the company’s largest growth engine and its main path to competing with the category leaders.3 5 8