- The KOSPI index’s recent brutal selloff—dropping below 6,000 for the first time since July 31—reflects a deeper reassessment than typical semiconductor cycle noise. According to James Ooi, chief market strategist at Tiger Brokers, the recent weakness signals a fundamental repricing of how much future AI growth is already embedded in memory-sector valuations. The immediate visible catalyst was CXMT’s announced progress on more efficient DRAM architecture (China’s answer to Samsung and SK Hynix dominance). That news triggered classic competitive anxiety: Korean semiconductor players facing potential disruption from a Chinese competitor. But the scope of the selloff—extending beyond DRAM producers to flash-memory makers and hard-drive manufacturers—suggests something broader is happening. Investors aren’t just worried about CXMT competition. They’re questioning the durability of memory-sector profit margins themselves. That’s a valuation signal, not a competitive signal. It says: “We’ve been assuming AI capex will drive memory prices higher indefinitely. We’re no longer confident in that assumption.”
- The key insight from Ooi is the indirect selling: SanDisk (flash memory, part of Western Digital) and Seagate (hard drives) both sold off despite having no direct competitive exposure to CXMT’s DRAM technology. Neither company makes DRAM. Neither is directly threatened by Chinese architectural advances in memory cells. Yet both got caught up in the sector-wide repricing. That pattern indicates investors are engaging in a broader margin durability reassessment across the entire memory value chain. The logic: supply shortages have driven memory prices higher, benefiting producers across DRAM, NAND flash, and hard drives. But supply shortages are temporary. As AI capex normalizes or supply catches up, memory prices will compress. Profit margins—currently at historically elevated levels—will contract. The question Ooi raises is whether equity valuations have properly priced in that margin compression. The evidence suggests they haven’t. The KOSPI selloff is the market recalibrating: “Memory margins were inflated by supply constraints. Those constraints won’t last. Valuations need to fall.” This is valuation repricing, not fundamental demand destruction. But valuation repricing can be severe.
- Ooi’s conclusion—”The next phase of AI investing could become more selective”—is the critical takeaway. For the past 18 months, AI capex has been relatively undiscriminating: buy memory, buy semiconductors, buy anything that touches AI infrastructure. Indiscriminate buying drove broad chip-sector rallies and inflated memory valuations. But if investors now believe memory-sector margin tailwinds are temporary, the next phase becomes more granular. Capital will flow toward: (1) AI beneficiaries with durable competitive advantages (not commoditized memory suppliers); (2) AI applications with proven ROI (not AI infrastructure with abstract future value); (3) selective chip picks with secular tailwinds beyond AI (not cyclical commodity plays). This is the shift from “AI infrastructure” to “AI outcomes.” It’s the shift from “buy memory because AI” to “buy this specific software/hardware combo because it solves a real customer problem.” For memory suppliers, that’s a structural headwind. Ooi isn’t predicting memory demand collapses. He’s predicting that memory become a commodity with compressed margins, not a premium-multiple industry. And that repricing could be painful for equities currently priced as if margin expansion continues.
What Happened?
The KOSPI index experienced a significant selloff, dropping below 6,000 (lowest since July 31, 2026), reflecting what James Ooi, chief market strategist at Tiger Brokers, characterizes as a broader reassessment of how much AI-driven future growth is already reflected in semiconductor and memory-sector valuations. The immediate catalyst was China-based CXMT’s progress on developing more efficient DRAM architecture, renewing competitive concerns for South Korean DRAM dominance (Samsung, SK Hynix). However, Ooi notes that the selloff extended beyond direct DRAM competitors to include SanDisk (flash-memory) and Seagate (hard-drive), both companies with no direct competitive exposure to CXMT’s DRAM technology. This broad-based weakness across the memory value chain suggests investors are reassessing the durability of elevated profit margins in the memory sector. Ooi attributes current high memory prices to supply shortages driven by AI capex, but questions whether those favorable supply conditions will persist. He argues that equity valuations may not be properly pricing in margin compression once supply constraints ease.
Why It Matters?
The KOSPI selloff and cross-asset weakness in memory producers signals a critical inflection in AI investment cycles: the shift from undiscriminating “buy everything AI-related” to selective “buy AI plays with durable competitive advantages.” Memory-sector valuations have been supported by two tailwinds: (1) AI capex driving demand, and (2) supply constraints keeping prices elevated. If investors now believe supply constraints are temporary and memory is becoming a commoditized layer in AI infrastructure, profit margins face structural pressure. Ooi’s analysis that the next phase of AI investing will be “more selective” implies capital will rotate away from commodity memory suppliers toward AI software, applications, and proprietary chips with differentiated value propositions. This validates the broader session theme: the distinction between AI hype and AI economics. Memory suppliers benefited from hype (any AI capex helps). Going forward, beneficiaries will be selective (only AI that drives real revenue and margin expansion). For memory producers, that’s a multiples compression risk even if volumes remain stable. For the market, it signals the AI euphoria phase may be giving way to a profitability reality phase. This is consistent with earlier session articles (306: Accenture deflating; 315: Coinbase quantum risk) that question whether AI capex translates to shareholder value creation.
What’s Next?
Monitor memory-sector guidance over the next 2-4 quarters for evidence of margin pressure. If Samsung, SK Hynix, Micron, and Kioxia all guide to lower or flat margins despite stable volumes, it validates the “supply premium” thesis and confirms the repricing is justified. If margins hold, it suggests the market overreacted. Watch for capital allocation shifts in chip-sector equity funds. If fund managers rotate away from memory suppliers into AI software and application-layer plays, it suggests professional investors are internalizing the “selectivity” message. Track CXMT’s progress and any announcements from Chinese memory competitors. If CXMT reaches production and proves viable, it validates the competitive threat and accelerates margin compression. If CXMT stalls, it may reduce perceived near-term pressure. Monitor AI capex guidance from mega-cap tech (Meta, Google, Amazon, Microsoft) in Q3/Q4 earnings. If capex guidance moderates or flattens, it suggests AI infrastructure investment may be peaking, reducing demand-side support for memory prices. If capex continues accelerating, it may challenge the “supply constraint relief” thesis. Finally, watch how equity analysts reset KOSPI and memory-sector valuations. If analyst consensus multiples compress by 15-25%, it suggests the market is re-pricing memory to commodity levels. If multiples remain elevated, it signals conviction that margin pressure is temporary.
Affected Tickers and Coins: KOSPI | Samsung | SK Hynix | WDC (SanDisk parent) | STX | MU | CXMT (Chinese competitor; unlisted in US)
Source: Wall Street Journal
