SanDisk and Western Digital Jump 6% as Traders Battle Over the AI Storage Stock Melt-Up

Shares of SanDisk (NASDAQ:SNDK | SNDK Price Prediction) are up 6% in Friday morning trading, changing hands near $1,989, while Western Digital (NASDAQ:WDC) stock up 6% to $561. The bid adds another leg to a furious AI storage melt-up that has lifted memory and disk-drive names into record territory.

SNDK stock has staged one of the most extreme runs in the U.S. market this year, as it’s up 724% year to date (YTD) and 4,638% over the past 12 months. WDC stock has gained 224% YTD and 902% over the past year, riding the same AI infrastructure tailwind that has pulled NAND and hard-disk drive demand higher.

The catalyst extends well beyond any single headline. The market is debating whether this is the early innings of a multi-year AI memory supercycle or a late-stage melt-up vulnerable to a sharp reversal.

AI Storage Demand Fuels the Bid

The fundamentals behind SanDisk’s run have been hard to dispute. The company’s Q3 FY2026 results, reported April 30, delivered EPS of $23.41 versus a $14.66 consensus and revenue of $5.95 billion, up 251% year over year (YoY). Furthermore, SanDisk’s data-center segment revenue jumped 645% YoY to $1.47 billion.

SanDisk guided Q4 FY2026 revenue to $7.75 billion to $8.25 billion and non-GAAP EPS of $30 to $33. CEO David Goeckeler called the quarter “a fundamental inflection point for SanDisk” as mix shifts toward datacenter customers under multi-year supply contracts.

Western Digital Rides the HDD Tailwind

Western Digital’s own Q3 FY2026 report delivered non-GAAP EPS of $2.72 against a $2.39 consensus and revenue of $3.34 billion, up 46% YoY. The company’s non-GAAP gross margin cleared 50% for the first time in recent memory as AI workloads tightened hard-disk drive supply.

Western Digital’s management guided its Q4 FY2026 revenue to roughly $3.65 billion and non-GAAP EPS of $3.25, plus or minus $0.15. CEO Irving Tan stated that “virtually every AI workload, from training, inference, agentic AI to physical AI, creates data that is stored persistently and cost-efficiently on HDDs.”

Bulls Battle Bears on Sustainability

The bull case rests on structural undersupply. SanDisk has reportedly locked in approximately $42 billion in multi-year supply agreements, and Susquehanna carries a $2,000 price target on SNDK stock, the highest on the Street. WallStreetBets sentiment scores ran 75 to 82 on Thursday, firmly in very bullish territory.

The bear case is more skeptical. SNDK stock trades at a stretched valuation after its 12-month rip, and insider selling has surfaced, including a director offloading 579 shares near $1,503 in early May. A separate bearish cohort on the “stockmarket” subreddit posted sentiment readings of 35 to 45, calling the move overextended and ripe for a reversal.

What to Watch Next

The near-term question is whether Friday’s bid holds into the close. With SNDK stock near record highs and WDC stock just off its own peak, intraday volatility could intensify as traders rotate around the AI memory complex.

Investors can keep an eye on incoming NAND and HDD pricing data, which has been the dominant signal for the group all year. The next earnings cycle could either validate the lofty guidance or reset expectations after this run.

Position sizing matters here. The structural tailwinds may be real, but the velocity of the move argues for measured exposure rather than chasing strength in SNDK and WDC.