SanDisk Plunges 11%, Micron and Western Digital Slide 10% as Korean Market Crash Hits Memory Chips

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By David Moadel Published

Quick Read

  • SanDisk (SNDK) plunged 11% while Western Digital (WDC) and Micron (MU) dropped 10% Tuesday morning, reversing off record highs after surging in 2026.

  • The Roundhill Memory ETF (DRAM) crashed 14% as South Korea's Kospi fell 10%, dragging SK Hynix and Samsung down over 12%.

  • Irrespective of the share-price rout, SanDisk's Datacenter revenue surged 645% YoY and Micron guided Q3 FY2026 to $33.5 billion, with Wednesday's Micron earnings being the next key catalyst.

  • Act now: the analyst who called NVIDIA in 2010 just named his top 10 AI stocks — and Micron Technology didn't make the cut. Grab the names FREE today.

SanDisk Plunges 11%, Micron and Western Digital Slide 10% as Korean Market Crash Hits Memory Chips

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Shares of SanDisk (NASDAQ:SNDK | SNDK Price Prediction) are leading a sharp memory-chip selloff Tuesday morning session, with SanDisk stock down 11% to $2,027.50. The decline comes one day after the stock closed at a record high, capping a stunning run higher.

Micron Technology (NASDAQ:MU) stock is sliding alongside it, off 10% to $1,085, while Western Digital (NASDAQ:WDC) shares are down 10% to $658. The triple-digit moves are arriving directly off Monday’s record-setting close.

The catalyst is broader than memory itself. A global risk-off wave started in Asia overnight and rolled into U.S. memory names that had run up vertically on AI-driven data-center demand.

Korean Market Crash Triggers the Reversal

South Korea’s Kospi closed 10% lower on Tuesday, with memory giants SK Hynix and Samsung Electronics both sliding more than 12%. Trading was briefly suspended for about 20 minutes to slow the cascade, and AI-linked stocks fell across Japan and Europe.

Because SK Hynix, Samsung, and Micron are among the top holdings of the Roundhill Memory ETF (NYSEARCA:DRAM), the contagion was immediate. The DRAM ETF is down 14% pre-market, crashing despite SanDisk and Western Digital’s HDD/NAND mix differing from pure DRAM exposure.

This looks more like sell-the-news profit-taking after an extreme rally than a memory-specific fundamental break. SanDisk stock had gained 858% year to date (YTD), Micron stock was up 325% YTD, and Western Digital stock had climbed 326% YTD prior to the Tuesday morning sell-off. Names that move like that tend to reverse hard on any wobble in confidence.

Fundamentals Still Look Strong

The fundamentals remain solid across the group. SanDisk’s most recent Q3 FY2026 report showed revenue of $5.95 billion against a $4.73 billion consensus, with the Datacenter segment up 645% year over year (YoY) and gross margin expanding to 78%.

SanDisk CEO David Goeckeler described the quarter as “a fundamental inflection point” driven by mix shift toward datacenter customers. Micron’s last report showed revenue of $23.86 billion with gross margin at 74%, and the company guided Q3 FY2026 revenue to $33.5 billion plus or minus $750 million.

That tension, robust fundamentals running into a parabolic chart, is exactly what split sentiment overnight. The debate playing out is whether this is a temporary blip or the start of a real correction after these names surged enormously over the past year on AI-driven data-center demand.

Retail Sentiment Cools Into Micron’s Report

Reddit chatter has cooled noticeably. Micron’s aggregate sentiment slipped from 81 (Very Bullish) early Monday to 56 (Neutral) by Tuesday morning. A top r/options thread, “Micron earnings Tuesday and the bar feels insanely high, anyone else nervous?”, captures the pre-earnings jitters cleanly.

SanDisk’s Reddit sentiment slid from 72 (bullish) Monday to 45 (neutral) by early Tuesday. StockTwits sentiment on Micron and SanDisk also turned bearish overnight, consistent with broad de-risking across high-beta AI plays.

What to Watch Next

The next defined catalyst is close. Micron is scheduled to report fiscal Q3 2026 earnings on Wednesday, June 24, after market close, and that report will likely set the tone for the entire memory complex.

Investors can watch how SanDisk, Micron, and Western Digital shares behave throughout the day and how the Roundhill Memory ETF trades. Given the volatility, investors may consider sizing their positions modestly until the dust settles.

The blip-versus-correction debate won’t resolve today. Micron’s report tomorrow is the next anticipated data point, and it arrives with high expectations.

Photo of David Moadel
About the Author David Moadel →

David Moadel is financial writer specializing in stocks, ETFs, options, precious metals, and Bitcoin. David has written well over 1,000 articles for leading online publications, helping investors understand markets, income strategies, and risk.

His work has appeared in The Motley Fool, InvestorPlace, U.S. News & World Report, TipRanks, ValueWalk, Benzinga, Market Realist, TalkMarkets, Finmasters, 24/7 Wall St., and others.

With a master’s degree in education, David has taught at the elementary, high school, and college levels. That teaching background shapes his writing style: clear, educational, and practical. David has also built a loyal social-media audience by providing trustworthy financial content on YouTube, X/Twitter, and StockTwits.

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