Shares of Personalis (NASDAQ: PSNL) plummeted 22.11% in after-hours trading on Tuesday following the release of its third-quarter 2025 financial results. While the company beat revenue expectations for Q3, its weaker-than-anticipated fourth-quarter guidance appears to have spooked investors.

Personalis reported Q3 revenue of $14.495 million, surpassing the analyst consensus estimate of $13.3 million. However, this figure represents a significant 44% year-over-year decline. The company's net loss for the quarter stood at $21.652 million, or $0.24 per share, which was better than the expected loss of $0.28 per share.

Despite the Q3 beat, Personalis's outlook for Q4 fell short of market expectations. The company forecasts Q4 revenue between $15.7 million and $20.7 million, well below the consensus estimate of $21.8 million. This disappointing guidance, coupled with the revised full-year 2025 revenue projection of $68.0 million to $73.0 million, likely contributed to the sharp stock decline. On a positive note, Personalis reported a 364% year-over-year growth in clinical test volume, driven by increased adoption of its NeXT Personal platform. However, this growth was not enough to offset investor concerns about the company's near-term financial performance.