Shares of Quanex Building Products (NYSE: NX) plummeted 20.61% in after-hours trading on Thursday following the release of the company's third-quarter earnings report, which fell short of analyst expectations and included lowered full-year guidance.

The building products manufacturer reported adjusted earnings per share of $0.69 for the fiscal third quarter, missing the consensus estimate of $0.84. While revenue came in slightly above expectations at $495.3 million compared to estimates of $491.6 million, the earnings miss and outlook cut led to the sharp sell-off. Quanex also recorded a significant $302.3 million non-cash goodwill impairment charge related to the re-segmentation of its business.

Adding to investor concerns, Quanex lowered its fiscal 2025 guidance. The company now expects full-year net sales of approximately $1.82 billion, down from its previous forecast of $1.84-$1.86 billion. More notably, Quanex cut its adjusted EBITDA outlook to around $235 million from the prior range of $270-$280 million.

George Wilson, Chairman, President and CEO of Quanex, commented on the results: "Although macroeconomic uncertainty and low consumer confidence, as well as operational issues related to the legacy Tyman window and door hardware business in Mexico that are ongoing but temporary in nature, posed challenges for us in our third quarter, we remain optimistic about our prospects for profitable growth and value creation." Despite management's optimism, the steep after-hours decline suggests investors are concerned about the earnings miss, compressed margins, and cautious outlook amid economic headwinds.