Shares of BillionToOne, Inc. (NASDAQ: BLLN) are soaring 66.67% in intraday trading on Thursday, marking a spectacular debut for the molecular diagnostics firm on the Nasdaq Global Select Market. The surge comes on the heels of the company's upsized initial public offering (IPO), which raised approximately $273.1 million in gross proceeds.

BillionToOne priced its IPO at $60 per share, selling nearly 4.6 million Class A shares. The offering was upsized from the initially marketed 3.85 million shares, which were originally priced between $49 and $55 each. The strong investor demand led to both an increase in the number of shares offered and a higher price point, signaling confidence in the company's prospects.

The Menlo Park, California-based company develops molecular diagnostic tests, including non-invasive prenatal screening and liquid biopsy for various diseases. BillionToOne's impressive financial performance likely contributed to investor enthusiasm, with the company reporting an 82% surge in revenue to $125.5 million for the first half of 2025, along with a narrowed net loss of $4.2 million. As the stock opened at $100 per share, significantly above its IPO price, it underscores the market's optimistic outlook on BillionToOne's growth potential in the expanding field of molecular diagnostics.