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存储芯片股7月13日暴跌15%:创纪录盈利下为何遭遇外资机构双杀?

2026-07-13 · 9 min · AlphaGBM
SK-HynixSamsungmemory-crashDRAMHBMKorea-stocksAI-semiconductorinstitutional-sellingpanic-sellingTSMC-earnings

What Happened to Memory Stocks on July 13, 2026?

South Korean memory semiconductor stocks suffered their most brutal single-day sell-off since the 2022 downturn cycle:

Stock July 13 Change Foreign Net Buy/Sell Institutional Net Buy/Sell
SK Hynix (000660.KS) -15.4% -705k shares -782k shares
Samsung Electronics (005930.KS) -10.7% -717k shares -3.246M shares

A significant characteristic of this sell-off was the complete lack of buyers—foreign and institutional investors simultaneously net-sold, with no buying interest whatsoever. Institutional selling in Samsung amounted to 3.25 million shares, suggesting systematic de-risking rather than sector rotation.

Why the Sell-off Amidst Record Earnings?

The divergence between price action and fundamentals is stark:

Samsung Electronics Q2 2026 Earnings (Announced July 7)

Metric Q2 2026 YoY Change
Revenue KRW 171T Record High
Operating Profit KRW 89.4T 19x YoY Growth

Samsung's 19x year-over-year profit growth—driven by AI chip demand and a surge in DRAM prices—represents the company's strongest quarterly performance in its history. Bernstein data shows DRAM contract prices were up +74% quarter-over-quarter, with another 13-18% expected in Q3.

However, in the weeks following this record-breaking earnings report, the stock has fallen approximately 35% from its June highs.

What Are the Six Signals to Distinguish Panic Selling from Fundamental Deterioration?

When memory stocks plunge to this extent, investors need a framework to judge whether the sell-off reflects genuine fundamental deterioration or emotional panic liquidation. Six key signals provide the basis for this judgment:

Signal 1: Earnings Revision Direction

Metric Current State Signal
Q3 DRAM contract prices +13-18% QoQ Still rising
Time to price peak H2 2027 12+ months away
HBM demand trajectory Accelerating AI data center buildout
NAND pricing Under pressure Divergence risk

For DRAM-centric companies, the earnings revision direction is still upward. The sell-off is occurring against a backdrop of improving fundamentals—not deteriorating ones. This is a typical characteristic of emotion-driven selling.

Signal 2: Cross-Market Contagion Pattern

US-listed memory-related instruments showed extreme stress on July 13:

Instrument Pre-market/Intra-day Move
HK-listed 2x Leveraged Memory ETF -10% to -12%
Micron (MU) Pre-market -5.4%
SOXL Put/Call Ratio 4.26 (Z-score: 2.7 standard deviations)

The SOXL Put/Call Ratio of 4.26 represents a 2.7 standard deviation event—extreme bearish sentiment, historically occurring less than 4 times per year. However, the historical contrarian long win rate at this level is only 20%, suggesting that the panic may need more time to fully resolve.

Signal 3: Leveraged Product Flows

Hong Kong-listed leveraged ETFs tracking SK Hynix saw significant outflows:

Metric Value Context
07709 (2x Hynix ETF) Net Outflow $1.56B 10.4% of trading volume
30-day Percentile P93 Approaching extreme outflows

A P93 reading means that in the past 30 trading days, only 7% of the time have outflows exceeded this level—indicating accelerated leveraged capital withdrawal, but not yet reaching maximum panic liquidation levels.

Signal 4: Volatility Premium

Underlying Asset Implied Volatility Percentile
Broad Semiconductor >80th percentile
Memory-specific options Elevated across all expiries

Option prices across the entire semiconductor sector are expensive. When implied volatility is this high, it typically means the market has already priced in significant further downside.

Signal 5: Composite Panic Index

Our composite panic index, tracking four major memory stocks, shows all four stocks in the panic zone, but not yet at capitulation levels:

Stock Panic Index Zone
SK Hynix 47.4 Panic
Samsung Electronics 45.9 Panic
Micron 42.9 Panic
Sandisk (WDC) 41.7 Panic

The panic zone (40-60) indicates elevated stress but not extreme pessimism. Historical capitulation bottoms for memory stocks typically occur when the index exceeds 60 (extreme panic), suggesting the emotional cycle may not be complete.

Signal 6: Catalyst Calendar Proximity

The most important near-term signal is the proximity of two key earnings events:

Event Date Importance
TSMC Q2 Earnings July 16 Sets the tone for the entire semiconductor capex cycle
SK Hynix Q2 Earnings July 22 HBM revenue growth + potential buyback
Samsung Full Q2 Report Late July Detailed business segment data

TSMC's earnings report on July 16—just 3 days away—is the single most important catalyst. As the world's largest foundry, TSMC's guidance on AI chip demand, advanced packaging capacity, and capital expenditure plans will either validate or challenge the current sell-off logic.

What is DRAM-NAND Divergence and Why is it Important?

A crucial divergence is emerging within the memory sector:

DRAM (AI-Driven Demand)

NAND (Traditional Storage)

Investors treating memory as a monolithic block are missing this critical divergence. SK Hynix holds approximately 50% of the global HBM market share, placing it on the structurally advantaged side. However, its stock is being indiscriminately sold off alongside stocks with NAND exposure.

What Does the Institutional Selling Pattern Tell Us?

The simultaneous selling by foreign and institutional investors warrants careful analysis:

Foreign Investor Movements (KRX)

Date Hynix Foreign Net Buy/Sell Samsung Foreign Net Buy/Sell
July 9 +88k shares (Net Buy) Net Sell
July 10 Mixed Mixed
July 13 -705k shares -717k shares

This reversal from net buying on July 9 to massive selling on July 13 suggests this is not a planned portfolio reduction but rather forced liquidation or risk-driven action—possibly triggered by margin calls on leveraged positions or systematic de-risking by quant funds.

Goldman Sachs Holdings (CCASS Data)

Goldman Sachs' Hong Kong department simultaneously sold leveraged products for both Samsung and Hynix, consistent with prime broker de-risking directives rather than a directional conviction.

What Should Investors Focus On This Week?

TSMC Earnings (July 16) - The Decisive Event

TSMC's Q2 report will answer three questions that will determine whether the memory sell-off continues or reverses:

  1. AI chip demand: Are NVIDIA/AMD orders accelerating or peaking?
  2. CoWoS capacity: Is advanced packaging (key for HBM integration) still a bottleneck?
  3. 2026-2027 capex guidance: Does TSMC believe the AI infrastructure cycle is extending?

A bullish TSMC report could trigger a sharp rebound in memory stocks, as it would confirm the AI-driven demand thesis supporting DRAM pricing power. A cautious report, conversely, would validate current fears and could prolong the sell-off.

SK Hynix Q2 Earnings (July 22)

Key analyst expectations for Hynix Q2:

Metric Consensus Bullish Scenario Bearish Scenario
Operating Profit ~KRW 65T KRW 70T+ KRW 55-60T
HBM Revenue Contribution 50%+ 55%+ 45%
Buyback Announcement Expected Sizeable plan Delayed

Notably, some analysts are forecasting operating profit as low as KRW 60.4T—about 8% below consensus—which would disappoint an already fragile market.

Core Conclusion: Framework Over Emotion

The memory stock plunge on July 13 is a classic case of tension between fundamental strength and market sentiment. Our six-signal framework's assessment:

The direction of memory stocks over the next two weeks will not depend on today's panic, but on whether TSMC and Hynix earnings confirm that AI-driven demand is robust enough to support current valuations—or if the market's fear of slowing growth is already materializing.


AlphaGBM Research | Data Sources: Korea Exchange (KRX), CCASS Settlement Data, Bloomberg Options Data, Bernstein Research Reports. Published on July 13, 2026. This article is for informational analysis only and does not constitute investment advice.

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