Shares of Westinghouse Air Brake Technologies (WAB), also known as Wabtec, plunged 5.34% in pre-market trading on Wednesday following the release of its third-quarter earnings report. Despite beating earnings estimates, the locomotive parts maker's tightened full-year guidance and ongoing concerns about U.S. tariffs weighed heavily on investor sentiment.

Wabtec reported adjusted earnings per share of $2.32 for the third quarter, surpassing analysts' expectations of $2.27. The company's net sales grew 8.4% to $2.88 billion, aligning with market estimates. However, the positive quarterly results were overshadowed by the company's decision to tighten its 2025 profit forecast range to $8.85-$9.05 per share, down from the previous upper limit of $9.15.

The stock's sharp decline appears to be driven by growing concerns over the impact of U.S. tariffs on Wabtec's performance. The company noted that higher tariffs and working capital issues partially contributed to a decrease in cash provided by operations, which fell to $367 million from $542 million in the same quarter last year. As Wabtec navigates headwinds from shifting U.S. trade policies, investors seem wary of potential margin pressures and the company's ability to maintain growth in an increasingly challenging economic environment.