Shares of Tandem Diabetes Care (TNDM) surged 14.54% in pre-market trading on Thursday, following the release of its impressive first-quarter 2025 financial results. The medical device company, specializing in insulin delivery systems, reported revenue that significantly exceeded Wall Street expectations and demonstrated strong growth across its markets.

Tandem Diabetes Care announced Q1 revenue of $234.42 million, representing a 22.3% year-over-year increase and handily beating the analyst consensus estimate of $220.20 million. The company's performance was driven by robust sales growth both in the United States and international markets. U.S. pump sales grew 22% year-over-year, while sales outside the United States saw an even more impressive 35% increase.

Despite reporting a wider-than-expected GAAP loss per share, investors focused on the company's strong top-line performance and improved operational metrics. Tandem Diabetes Care reported an adjusted EBITDA margin of -2%, a significant improvement from -7% in the same quarter last year. Additionally, the company reaffirmed its full-year 2025 revenue guidance of $997 million to $1.007 billion, aligning closely with analysts' expectations. This combination of strong current performance and positive future outlook has fueled investor optimism, leading to the substantial pre-market stock price increase.