Western Digital shares tumbled 5.09% during the regular trading session, as investors rushed to lock in gains ahead of the company's highly anticipated quarterly earnings release after the market close.

The sharp decline reflects mounting profit-taking pressure after a strong run-up in the stock, fueled by recent analyst upgrades, including a significant price target hike from BNP Paribas. With the earnings call looming, uncertainty over whether Western Digital can deliver sufficiently robust AI demand guidance to justify its elevated valuation prompted many to sell.

The broader storage sector has been under pressure, with Western Digital already down 26% from its June all-time high amid a July selloff that wiped out over $150 billion in market value from peers. The high-stakes earnings report is seen as a critical test of whether storage demand can continue to meet sky-high expectations, and traders are bracing for potential volatility.