Zai Lab Ltd (ZLAB) stock surged 5.18% in intraday trading on Thursday, following the release of its first-quarter 2025 financial results. The biopharmaceutical company reported a narrower-than-expected loss per share, which has sparked investor optimism despite missing revenue estimates.

For the quarter ended March 31, Zai Lab posted an adjusted loss of $0.45 per American depositary share, outperforming Wall Street's consensus estimate of a $0.55 loss. While the company's revenue increased by 22.2% year-over-year to $106.49 million, it fell short of analysts' expectations of $113.15 million. Despite the revenue miss, the improved bottom line has evidently pleased investors.

Adding to the positive sentiment, Zai Lab reaffirmed its full-year 2025 revenue guidance of $560 million to $590 million, aligning with analysts' expectations of $565.4 million. The company's ability to narrow its losses while maintaining its revenue outlook has boosted investor confidence, driving the stock's significant uptick. This rally comes as a welcome change for Zai Lab, whose shares had previously fallen by 21.5% in the preceding quarter.