Waters Corporation (WAT) shares tumbled 6.13% in pre-market trading following the release of its fourth-quarter 2025 financial results and forward guidance. The scientific instrument maker reported quarterly earnings and revenue that exceeded analyst expectations but provided first-quarter 2026 earnings per share guidance that fell short of estimates.

The company reported Q4 non-GAAP earnings of $4.53 per diluted share, beating the FactSet consensus estimate of $4.51. Revenue for the quarter reached $932.4 million, also surpassing the expected $928.3 million. Despite this strong performance, Waters' outlook for the current quarter disappointed investors.

For Q1 2026, Waters guided for non-GAAP EPS in the range of $2.25 to $2.35, below the analyst consensus of $2.51. The company is also in the process of combining with BD's Biosciences and Diagnostic Solutions business, a transaction expected to close imminently. While this combination significantly expands Waters' revenue base, investors appear focused on the near-term earnings guidance miss, driving the stock lower in pre-market activity.