MasterBrand, Inc. (MBC) experienced a significant after-hours plunge of 16.71% following the release of its fourth quarter and full year 2025 financial results.

The sharp decline was driven by the company reporting a quarterly adjusted loss per share of $(0.02), which missed analyst consensus estimates of $0.14 by 114.29%. This represents a 109.52% decrease compared to earnings of $0.21 per share from the same period last year. While quarterly sales of $644.6 million beat estimates, they still decreased 3.46% year-over-year, with the company noting a net loss margin of -6.5% for the quarter.

Further pressuring the stock was weak forward guidance, with MasterBrand expecting first quarter 2026 net sales to decrease by a mid-to-high single-digit percentage year-over-year. The company also anticipates its full year 2026 addressable market to be down mid-single digits. In response to current demand levels, MasterBrand announced a $30 million cost rationalization program expected to be achieved in 2026.