The best-performing stock in the S&P 500 this year has given back a quarter of its value in four sessions.

SanDisk Corp. (NASDAQ:SNDK) is down 24.8% week-to-Thursday, on track for its worst weekly performance since March 2025.

No warning. No bad news. Just the bill coming due.

The stock now trades nearly 39% below the record it set in June, a drawdown that would qualify as a crisis in almost any other name.

For SanDisk, it barely dents the chart.