BillionToOne, Inc. (NASDAQ: BLLN) experienced a sharp after-hours plunge, with its stock price dropping 23.32% following the release of its second-quarter 2026 financial results. The significant decline came as investors reacted to a bottom-line earnings miss, despite the company reporting top-line growth and revenue that slightly exceeded analyst expectations.

The company reported quarterly earnings of $0.15 per share, which fell short of the consensus estimate of $0.19 by 21.05 percent. While this figure represents a 50 percent increase compared to the $0.10 per share earned in the same quarter last year, the miss against market expectations appeared to be the primary driver of the negative sentiment. On the revenue side, the company posted sales of $109.4 million, a 30.98 percent year-over-year increase, which narrowly beat the analyst estimate of $109.365 million.

Alongside the quarterly figures, BillionToOne reiterated its full-year 2026 revenue guidance of $450 million to $465 million. The after-hours sell-off indicates that the market focused heavily on the earnings per share shortfall, outweighing the modest revenue beat and the reaffirmed annual outlook.