Stock Markets June 18, 2026 10:32 AM

Chipmakers and Storage Names Drive Big Intraday Moves; IBM Lags

A broad cross-section of mega-, large-, mid- and small-cap stocks posted sizeable gains and losses as sector-specific news and corporate actions moved markets

By Priya Menon
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SNDK WDC MRVL INTC AMAT

Stocks across market-cap tiers swung sharply on Thursday, led by gains in storage and semiconductor names and headline-driven moves among large- and mid-cap names. Western Digital and SanDisk were among the notable winners, while IBM and several other names traded lower. Corporate announcements including acquisitions, board appointments and clinical trial results contributed to the day’s volatility.

Chipmakers and Storage Names Drive Big Intraday Moves; IBM Lags
SNDK WDC MRVL INTC AMAT
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Key Points

  • Storage and semiconductor names, including SanDisk and Western Digital, led gains among mega-cap stocks.
  • Corporate actions and news - acquisitions, store openings, board appointments, share offerings and clinical trial outcomes - influenced large- and mid-cap movers across technology, retail and biotech sectors.
  • Several smaller-cap and micro-cap issuers registered outsized percentage moves, reflecting concentrated trading and company-specific catalysts.

Thursday’s trading session produced pronounced volatility across market capitalizations, with multiple companies recording double-digit percentage moves on company-specific developments and sector momentum. The session saw storage and semiconductor stocks among the strongest performers, while certain software and biotech names posted declines tied to corporate headlines.

Mega-cap movers

  • SanDisk Corp-Exch (SNDK) +10.31%
  • Western Digital (WDC) +9.47%
  • Marvell Technology Group Ltd (MRVL) +9.03%
  • Intel Corp (INTC) +6.15%
  • Applied Matls Inc (AMAT) +6.2%
  • Kla-tencor Corp (KLAC) +6.46%
  • Micron Tech (MU) +6.69%
  • Lam Research Corp (LRCX) +5.31%
  • Qualcomm Inc (QCOM) +4.76%
  • IBM (IBM) -6.29%

Among the largest capitalization names, several memory- and equipment-related stocks posted strong advances, while IBM was a notable decliner for the session.

Large-cap activity and corporate headlines

  • Accenture Ltd (ACN) -14.04% - Accenture to acquire majority stake in Dragos for $4.2 billion
  • Cognizant Technology Solutio (CTSH) -6.29% - Cognizant integrates ServiceNow AI agents with Neuro platform
  • Kroger Co (KR) -6.84%
  • New Providence Acquisition Corp N (ASTS) -8.04%
  • Wayfair Inc (W) +9.68% - Wayfair to open large-format store in Princeton, New Jersey
  • FormFactor (FORM) +7.15%
  • Roblox Corp (RBLX) +7.38%
  • Allegro Microsystems Inc (ALGM) +8.3% - Allegro MicroSystems appoints Brian White to board
  • Entegris Inc. (ENTG) +7.35%
  • DRAM (DRAM) +9.08%

In the large-cap universe, acquisition news and strategic partnerships were among the drivers, alongside store expansion plans that supported retail-linked names.

Mid-cap movers

  • SNXX (SNXX) +19.14%
  • Vishay Intertechnology Inc (VSH) +12.6%
  • Diodes Inc (DIOD) +11.29%
  • Fermi America LLC (FRMI) +11.95%
  • MUU (MUU) +13.56%
  • Ekso Bionics Holding (CHRN) +9.9%
  • Legend Biotech Corp (LEGN) -14.05% - Legend Biotech launches $225 million public share offering
  • OM Asset Management PLC (AAMI) -10.64%
  • Novocure Ltd (NVCR) -17.76% - Novocure’s glioblastoma trial fails primary endpoint
  • CF Acquisition Corp VI (RUMBW) +14.5%

Mid-cap movement included several industrial and semiconductor suppliers as well as biotech names reacting to financing and clinical-trial outcomes.

Small-cap and other movers

  • INTC +7.52%
  • QCOM +5.29%
  • AMAT +6.25%
  • SNDK +10.67%
  • LRCX +5.56%
  • CTSH -6.41%
  • KLAC +6.2%
  • MRVL +11.74%
  • ACN -14.68%
  • KR -6.5%
  • IBM -5.91%
  • MU +7.99%
  • WDC +8.62%
  • ENTG +8.00%
  • AOSL +12.79%
  • DIOD +12.78%
  • FORM +6.45%
  • SWBI +20.47%
  • VSH +11.69%
  • CHRN +9.63%
  • W +10.07%
  • AAMI -9.82%
  • NVCR -18.82%
  • MULL -1.92%
  • FVRR +12.47%
  • REAL +10.54%
  • LEGN -14.2%
  • ASTS -7.54%
  • BFLY +34.99%
  • ALGM +9.19%
  • RBLX +6.91%
  • SLBT -13.9%
  • INTW +14.22%
  • FRMI +12.53%
  • SNXX +20.31%
  • DRAM +10.28%

The small-cap list repeats some larger names but also highlights outsized gains in specific micro- and small-cap issuers, including a strong jump for BFLY and elevated moves for trading- and device-oriented companies.

Selected company-specific notes

  • Accenture’s planned majority stake purchase in Dragos is valued at $4.2 billion, a transaction that coincided with a steep decline for Accenture’s shares.
  • Wayfair confirmed plans to open a large-format store in Princeton, New Jersey, and traded higher on the announcement.
  • Legend Biotech began a $225 million public share offering, a development accompanied by a share-price decline.
  • Novocure reported that its glioblastoma trial did not meet the primary endpoint, a result associated with a notable share drop.
  • Longview Acquisition (BFLY) and Butterfly Network reported supply of ultrasound technology for a Midjourney scanner and BFLY shares surged.
  • Smith & Wesson (SWBI) posted Q4 results and revenue that topped estimates and rallied sharply.

Traders and investors navigating the session encountered a mix of momentum-driven moves and reactions to corporate announcements, with activity concentrated in technology, semiconductors, storage, retail and biotech-related names.


Note on coverage - The lists above capture headline percentage moves and company-specific highlights reported during Thursday’s market session.

Risks

  • Share-price declines tied to corporate events - such as Accenture’s acquisition announcement and Legend Biotech’s $225 million share offering - may indicate heightened event-driven volatility in the technology and biotech sectors.
  • Clinical-trial setbacks, exemplified by Novocure’s glioblastoma trial failing its primary endpoint, create downside risk for biotech and healthcare-linked names.
  • Concentrated moves in small-cap and micro-cap stocks, including both sharp rallies and steep drops, imply elevated liquidity and headline risk for smaller issuers across sectors.

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