SNDK, WDC, MU, SMCI Stock Are The Top S&P 500 Gainers — Sustained Corporate Demand Anchored By SanDisk's Rosy Outlook Is Aiding Memory Stocks

Shares of leading memory chipmakers soared on Thursday as SanDisk’s optimistic long-term margin and revenue projections restored investor confidence.

• SanDisk shares jumped 15% to the top of the S&P 500, followed by Micron Tech, Western Digital, and Super Micro. 
• SanDisk outlined long-term plans to sustain 80% non-GAAP gross margins through fiscal 2030, anchored by long-term supply agreements covering two-thirds of bits shipped by fiscal 2028. 
• Expanding AI inference workloads are projected to expand the enterprise data center flash market to 1.2 zettabytes by 2030. 

Memory and storage semiconductor equities surged to the top of the S&P 500 on Thursday, taking support from aggressive long-term growth guidance from SanDisk Corp.

SanDisk led the sector with a 15% surge, while Western Digital (WDC) gained 10%, SK Hynix (SKHY) climbed 8%, Micron Technology (MU) advanced 6%, and Super Micro (SMCI) rose 5% at the time of writing on Thursday. 

SanDisk Investor Day Signals Structural Sector Shift

The catalyst for the broader semiconductor surge stemmed directly from SanDisk’s 2026 Investor Day presentation, "SanDisk in Focus," during which executive leadership presented a multi-year financial framework that reset expectations across the memory ecosystem.

For fiscal years 2028 through 2030, SanDisk outlined targets for mid-to-high-teens compound revenue growth, supported by non-GAAP gross margins near 80%, operating margins near 75%, and adjusted free cash flow margins around 50%. The company also committed to returning all excess cash to shareholders following planned internal growth investments.

The bullish long-term framework directly benefited industry peers. Investors viewed SanDisk's pricing power and volume guarantees as evidence that memory economics are structurally improving, spilling over into higher valuations for Western Digital—which separated from SanDisk in 2025—as well as Micron (MU) and SK Hynix (SKHY). 

SanDisk leadership attributed the expansion to booming enterprise demand, noting the data center flash market is projected to reach 1.2 zettabytes by 2030.

Recent Earnings Performance And Full-Year Outlook

Memory and server suppliers reported strong recent quarterly results despite brief market anxiety. SanDisk posted Q4 fiscal revenue of $8.97 billion, a 51% sequential surge led by data center flash demand, and projected Q1 fiscal 2027 revenue of $10.3 billion to $10.8 billion.

Western Digital closed fiscal 2026 with Q4 revenue up 44% year-over-year to $3.75 billion and non-GAAP EPS doubling to $3.56. Driven by data center expansion, it guided Q1 fiscal 2027 revenue to $4.1 billion.

Micron Technology generated $13.77 billion from cloud memory and $11.52 billion from data centers in Q3 this year, aided by its leadership in high-bandwidth memory, while forecasting revenue of $50 billion in Q4. Super Micro Computer saw higher backlogs for liquid-cooled platforms as cloud and enterprise clients expanded AI server deployments, aligning with broader hardware growth.

SNDK stock has gained over 530% this year, Roundhill Memory ETF (DRAM) rose 112%, Tema ETF Trust (DISK) has lost 21% year-to-date. 

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