KLA-Tencor shares plummeted 6.28% during intraday trading on Tuesday, as a broad sell-off in the semiconductor equipment sector and pre-earnings jitters weighed heavily on the stock.

The decline came amid widespread pressure across the sector, with peers such as Applied Materials, Lam Research, and ASML Holding also posting notable losses. Investors turned cautious ahead of KLA-Tencor's fiscal fourth-quarter earnings report, scheduled for release after the market close. Consensus estimates project quarterly revenue of approximately $3.598 billion, up 16.72% year-over-year, and adjusted earnings per share of around $0.997, but uncertainty prevailed going into the results.

Adding to the negative sentiment, UBS recently lowered its price target on KLA-Tencor to $240 from $255 while maintaining a Neutral rating, reflecting a more guarded view on valuation. The combination of the lowered target, rising caution among bulls and bears, and sector-wide weakness drove the sharp intraday drop.