BillionToOne, Inc. (BLLN)

BillionToOne, Inc. is a molecular diagnostics company that develops highly sensitive DNA tests based on its proprietary technology for counting individual DNA molecules. The company is headquartered in Menlo Park, California.

Its prenatal business offers non-invasive tests performed on a blood sample from the mother that screen for chromosomal conditions and single-gene disorders in the fetus, marketed under the UNITY brand. In oncology, the company offers liquid biopsy tests under the Northstar name that help detect and monitor cancer and guide treatment decisions. Its customers include obstetricians, maternal-fetal medicine specialists and oncologists. BillionToOne completed its initial public offering on Nasdaq in 2025.