Shares of iRhythm Technologies Inc. (NASDAQ: IRTC) surged 13.43% in after-hours trading on Thursday, following the company's release of better-than-expected second-quarter results and raised full-year guidance. The digital health care company, known for its cardiac monitoring solutions, reported significant growth and strategic advancements that impressed investors.

For the second quarter of 2025, iRhythm reported a loss of $0.32 per share, substantially beating the analyst consensus estimate of a $0.48 loss. Revenue came in at $186.7 million, surpassing expectations of $173.9 million and representing a robust 26.1% increase from the same period last year. The company's gross margin improved to 71.2%, up from 69.9% in the previous year's quarter.

Adding to the positive sentiment, iRhythm raised its fiscal year 2025 guidance, now projecting revenue between $720 million and $730 million. The company also announced a strategic partnership with Lucem Health, aimed at utilizing predictive AI to help identify arrhythmias earlier. Furthermore, iRhythm presented results from two large-scale real-world studies at the American Diabetes Association's Scientific Sessions, demonstrating the critical role of early arrhythmia detection in at-risk populations. These developments, coupled with the strong financial performance, appear to have fueled investor optimism, driving the significant after-hours stock price increase.