KLA-Tencor shares tumbled 5.04% in pre-market trading, as the stock faced heavy selling pressure alongside the broader semiconductor equipment sector. The decline comes just hours before the company is scheduled to report its fiscal fourth-quarter earnings after the market close.

The semiconductor equipment group came under broad-based selling, with peers such as Applied Materials, Teradyne, Lam Research, ASML Holding, and Amkor Technology all posting notable declines. Analysts expect KLA-Tencor to post quarterly revenue of roughly $3.598 billion, up 16.72% year-over-year, and adjusted earnings per share of approximately $0.997, but institutional caution appears to be dominating sentiment ahead of the release.

UBS recently trimmed its price target on KLA-Tencor to $240 from $255 while keeping a Neutral rating, reflecting a more guarded view on valuation. The combination of a lowered price target, rising uncertainty between bulls and bears going into the report, and sector-wide weakness weighed heavily on the stock.