Nikkei Hits 66,329: US-Iran Truce Drives Global Rally

Nikkei Hits 66,329 All-Time High as US-Iran Truce Nears: Global Markets Rally in Synchronized Surge — Korea's Semiconductor Supercycle and the Inflation Dilemma

I've been tracking this synchronized global rally all week, and the breadth of the move tells me this is different from the typical risk-on bounce. may 29, 2026, will be remembered as the day global equity markets moved in lockstep to new all-time highs — a rare synchronized surge that spanned New York, Tokyo, and Seoul. The catalyst was a combination of geopolitics and technology: a historic US-Iran ceasefire Memorandum of Understanding reportedly in its final stages, awaiting only President Donald Trump's signature, combined with an accelerating AI-driven semiconductor supercycle that is reshaping supply chains from Silicon Valley to Suwon.

The S&P 500 rose 0.58% and the Nasdaq gained 0.91%, both closing at record levels. The Dow Jones Industrial Average eked out a 0.05% gain to a fresh all-time high. The Philadelphia Semiconductor Index — the benchmark for global chip stocks — rose 1.00%, providing the technical backbone for the tech-heavy indices. But the standout performer was Japan's Nikkei 225, which closed at 66,329 — its first-ever breach of the 66,000 threshold and the latest milestone in what has been a stunning multi-year recovery from Japan's decades-long stagnation.

US-Iran Ceasefire: Geopolitical Risk Premium Collapses

I think the geopolitical catalyst here is bigger than most realize. The US-Iran truce MOU is reportedly in its final form, with only Trump's final authorization remaining. The implications extend far beyond the Middle East. Lee Jae-man, head of research at Hana Securities, framed it as "more than just Middle East stabilization — it is a signal that global supply chain risks built up over years of tension are about to be substantially reduced." He expects oil prices to decline and logistics costs to normalize within the year as shipping routes through the Strait of Hormuz become de-risked.

The immediate market reaction is straightforward: geopolitical risk premium is being unwound across asset classes. The VIX volatility index declined, safe-haven currencies weakened, and cyclical stocks outperformed defensives globally. But I think the second-order effects are more interesting. A US-Iran detente removes one of the key arguments for maintaining elevated defense spending in the US and Europe, which has implications for the defense sector. It also opens the door for Iranian oil to return to global markets more freely, which would add downward pressure on crude prices and benefit oil-importing economies like Korea and Japan.

In my view, the past three months of global equity gains represent more than just a liquidity-driven momentum rally. We are entering a structural phase where earnings improvements and risk premium compression are operating in tandem — a combination that historically produces durable bull markets. Compared to the V-shaped recovery that followed the 2008 global financial crisis (March 2009 to April 2011, roughly 26 months), this current cycle has been both faster and broader. One notable exception: China. The ChiNext index plunged 2.11% on the same day as the rest of the world was celebrating records, highlighting the continued regulatory and structural headwinds facing Chinese equities.

Japan's Nikkei 66,329 close carries its own symbolic weight. The index that collapsed from its 1989 peak of 38,957, then spent three decades oscillating between 8,000 and 20,000, has now definitively broken out. It was only in February 2024 that the Nikkei finally surpassed its 1989 high for the first time. The move from that level to 66,329 in just over two years represents a compression of Japan's "lost decades" into a concentrated period of wealth creation. For Korean investors watching this, the question is whether the KOSPI — now at 8,476 with similar structural drivers — can follow a comparable trajectory.

Semiconductor Supercycle: HBM4E, Anthropic Investment, and Korea's Export Revolution

The semiconductor sector is the undisputed engine of the current global rally. Samsung Electronics achieved a significant technological milestone by shipping the world's first 12-layer HBM4E samples to customers, leapfrogging competitors in the high-bandwidth memory technology race. SK Hynix has surged to 89.72% of Samsung's market capitalization, reflecting the market's premium on HBM technological leadership.

Kim Dong-won, an analyst at KB Securities, captured the consensus view: "We have entered a supercycle phase where enormous capital is flooding into the memory semiconductor market, and this boom is fundamentally different from past cycles in its duration and structural backing." The data supports this view emphatically.

South Korea's full-year 2026 export forecast stands at $924.4 billion (approximately 1,290 trillion won), representing a 30.3% increase year-over-year. Within that total, semiconductor exports are projected at $350.1 billion — a staggering 101.1% increase from 2025, according to the Korea International Trade Association (KITA). These numbers, if realized, would push South Korea past the Netherlands to become the world's fourth-largest exporting nation, behind only China, the United States, and Germany.

The Bank of Korea has responded to this export boom by sharply upgrading its macroeconomic forecasts. The central bank now projects a 2026 current account surplus of $250 billion (349 trillion won) — more than double last year's $123 billion. In its optimistic scenario, the BOK forecasts real GDP growth of 3.1%, significantly above the estimated potential growth rate of 1.8%.

I believe this semiconductor supercycle is qualitatively different from the 2016-2018 memory boom in a way that most market analysis underappreciates. The 2016-2018 cycle was driven by server and mobile demand — essentially, the smartphone upgrade cycle combined with data center buildout. Both of those drivers were cyclical in nature, tied to product replacement cycles and capital spending budgets that could be deferred. This cycle is entirely AI workload-driven. When a major cloud service provider orders HBM memory, they are not speculating on future demand — they are filling orders for deployed AI inference infrastructure that is already generating revenue. The demand visibility is substantially higher, and the switching costs for customers once they integrate with a particular HBM supplier are substantially higher as well.

Equally significant: Samsung Electronics and SK Hynix participated as strategic infrastructure partners in Anthropic's Series H funding round. This is not a passive financial investment by a corporate venture arm. It signals that Korean semiconductor companies are evolving from commodity hardware suppliers to architectural partners in the AI ecosystem — a shift with profound implications for their long-term margin structures and valuation multiples.

Anthropic Series H: Why It Matters for Korean Semiconductor Stocks

Anthropic's Series H funding round, reportedly valued at over $10 billion, includes Samsung Electronics and SK Hynix as strategic infrastructure partners alongside existing investors. The terms of the partnership give these Korean memory makers preferential supplier status for Anthropic's compute infrastructure needs — effectively locking in long-term HBM and high-bandwidth memory supply agreements with one of the world's leading AI labs.

The strategic logic is clear. Anthropic needs guaranteed access to the most advanced HBM memory to train and deploy its Claude model series. Samsung and SK Hynix need guaranteed offtake agreements to justify the enormous capital expenditures required for HBM4E and next-generation fabrication facilities. It is a mutual dependency that creates structural competitive advantages for both sides. For Korean semiconductor stocks, it means that a portion of their future revenue is now contracted rather than speculative — a development that should support higher valuation multiples over time.

The Inflation Shadow: PCE 3.8% and AI Bubble Fears

Not all signals are flashing green, and it would be irresponsible to ignore the warning signs. The US April Personal Consumption Expenditure (PCE) price index rose 3.8% year-over-year — the highest reading since May 2023's 4.0% and significantly above the Federal Reserve's 2% target. On a month-over-month basis, PCE rose 0.4%, slightly above consensus expectations, according to the Bureau of Economic Analysis.

This inflation print complicates the Federal Reserve's policy trajectory considerably. Markets had been pricing in two to three rate cuts in the second half of 2026. A PCE reading at 3.8% makes those cuts far less certain. If inflation proves sticky and the Fed is forced to maintain or even tighten policy, the impact on risk assets — particularly high-multiple tech stocks — could be significant.

Goldman Sachs recently published a research note warning of overheating in the AI sector. The bank's analysts noted that massive capital expenditure on AI infrastructure — estimated at over $200 billion industry-wide in 2026 — could lead to short-term profitability deterioration if revenue generation from AI services does not materialize as quickly as expected. Park Sang-hyun, an economist at HI Investment & Securities, drew direct parallels to the 2000 dot-com bubble: "The underlying technological innovation is undeniable in both cases. The risk is that short-term capital concentration creates a pricing bubble that takes years to correct, even if the technology ultimately delivers."

I think the dot-com comparison is worth taking seriously, even if it is imprecise. The key difference from the 2020 pandemic semiconductor cycle — which saw a demand spike as work-from-home drove electronics purchases, followed by a sharp 2022 correction when demand normalized — is structural AI workload growth. Pandemic demand was pulled forward; AI demand is being created. That said, the current supercycle is highly selective, concentrated in HBM and high-bandwidth memory rather than all memory segments. Companies with heavy exposure to traditional DRAM and NAND flash face a critical strategic choice about how quickly they can pivot their product mix.

Korea's Export Revolution: Beyond Semiconductors

While semiconductor exports get the headlines — and deservedly so at $350.1 billion forecast — Korea's export boom is broader than just chips. Shipbuilding exports are projected to reach $38.5 billion in 2026, driven by the global LNG carrier and containership replacement cycle. Defense exports are tracking toward $18 billion, supported by recent contracts with Poland, Australia, and the UAE for K9 howitzers, K2 tanks, and FA-50 light attack aircraft. Nuclear power plant exports are emerging as a new growth vertical following the Czech Republic's decision to select Korea Hydro & Nuclear Power (KHNP) for a 24 trillion won project.

The common thread across all these sectors: they are all operating at or near capacity constraints. Korean shipbuilders have order backlogs extending to 2028-2029. Defense manufacturers are running three shifts. The semiconductor fabs are at near-100% utilization for HBM production. This level of capacity utilization across multiple export sectors simultaneously is historically unprecedented in Korea's export-driven economy and explains why the BOK was comfortable raising its growth forecast to 2.6%.

My assessment is that Korea's export diversification — from semiconductors to ships, defense, and nuclear — represents a structural improvement in the economy's resilience. A downturn in any single sector is now less likely to produce a recession because the other sectors can partially compensate. This is the most diversified Korea's export base has been in two decades, and it deserves more attention from global investors than it typically receives.

For global investors with Korean equity exposure, the PCE data point reinforces the importance of a barbell strategy: overweight semiconductor and AI infrastructure stocks that benefit from structural demand, while maintaining hedges against a rates-driven correction in high-multiple names. The Nikkei's 66,329 close is a powerful vote of confidence in Japan's reflation story, but Korea's export-driven rally has stronger earnings backing and is on more stable fundamental ground.

My Take: Why This Rally Has Legs — With One Big Caveat

I've been covering global equity markets for years, and the synchronized move we saw on May 29 is genuinely rare. The Nikkei at 66,329 isn't just a number — it represents Japan's definitive escape from three decades of deflationary stagnation. For Korean investors, the Nikkei's trajectory offers a roadmap: when structural reforms meet a global catalyst (AI), the results can be extraordinary. I think the KOSPI can follow a similar path, but the composition of the rally matters more than the headline level.

Here's what I think most analysis is getting wrong: everybody is focused on the US-Iran ceasefire as the catalyst, but I believe the real driver is the structural repricing of semiconductor assets. The AI-driven demand curve for HBM memory is not cyclical — it's a permanent shift in the technology landscape. Samsung's 12-layer HBM4E samples and the Anthropic Series H partnership are not quarterly events; they represent a structural re-ordering of the semiconductor supply chain that will play out over years, not months. When I look at the $350 billion Korea semiconductor export forecast, I see a number that's actually conservative if AI adoption accelerates.

The one caveat I keep coming back to: PCE at 3.8% is a real problem that the market is not fully pricing. The Fed cannot cut rates with inflation running at nearly double their target, and a hawkish Fed is the single biggest risk to the elevated multiples in the tech sector. My call is that the rally continues through Q3 2026 driven by earnings revisions, but we see a significant 10-15% correction in Q4 when the full weight of sticky inflation hits rate expectations. The playbook: overweight semiconductors, underweight long-duration tech, and keep 15-20% cash to deploy when the correction comes.

Related Keywords for Further Reading

• US-Iran ceasefire MOU impact global stock markets May 2026
• Nikkei 225 66,329 all-time high Japan rally analysis
• Korea semiconductor exports $350 billion 2026 forecast
• Anthropic Series H Samsung SK Hynix strategic investment
• US PCE March 2026 3.8% inflation Fed rate impact