Onto Innovation Inc. experienced a significant after-hours plunge of 6.38% following the release of its first-quarter financial results.

The semiconductor equipment maker reported quarterly sales of $264.178 million, which missed the analyst consensus estimate of $292.069 million by approximately 9.55%. While revenue rose 9.5% year-over-year to $291.9 million, the company's net income fell sharply by 47.35% to $33.8 million compared to the same period last year.

The negative market reaction was driven by the substantial earnings miss and the significant decline in profitability, with gross margin narrowing 3.6 percentage points to 50.1% and operating income sliding to $33.5 million. Although adjusted EPS of $1.42 met analyst expectations, the weaker-than-expected sales performance and dramatic profit contraction prompted investor concern.