Samsung, SK Hynix Both Hit Record Closing Highs as Japanese and Korean Markets Reach New Milestones
N.R. Finch
On June 18 Korea's KOSPI cleared 9,000 and the Nikkei 225 broke 71,000 for the first time, while Samsung and SK Hynix both set all-time closing records — three catalysts fired at once: early HBM4E sample delivery, a stock rally despite the BOJ rate hike, and an oil-price drop on the U.S.–Iran deal.
SK Hynix shipped samples early — how far ahead is it?
SK Hynix announced before the June 18 open that 12-layer HBM4E samples had reached key customers, at least two weeks ahead of the industry's July expectation.
HBM4E — next-generation high-bandwidth memory designed for AI training and inference — runs at up to 16 Gbps pin speed, with 20%+ better energy efficiency and ~17% lower thermal resistance than HBM4.
This means → SK Hynix has reclaimed the tempo in the HBM race. Samsung shipped its own 12-layer HBM4E samples first on May 29, but at 14 Gbps — one tier below SK Hynix's speed.
In plain terms = both companies have handed in their papers, but SK Hynix scored higher — and timed the announcement to land on the same day its stock hit a record.
Korea's KOSPI broke 9,000 — who drove it?
The KOSPI closed up 2.3% at 9,063.89, crossing 9,000 for the first time in history.
Samsung Electronics rose 4.62%; SK Hynix rose 6.51%. Both set all-time closing highs.
This means → the breakout was overwhelmingly powered by the two memory-chip giants — HBM4E's early delivery acted as the direct catalyst.
The Nikkei went from 60,000 to 71,000 in two months — is that normal?
The Nikkei 225 closed up 1.6% at 71,053.49, topping 71,000 for the first time. The TOPIX rose 1.4% to 4,068.18, also a record close.
The Nikkei first hit 60,000 on April 23. By June 18 it had cleared 71,000 — an 18% gain in under two months, with the past-year cumulative return exceeding 80%.
This reflects a rare acceleration phase — gains are compressing into shorter and shorter windows.
The BOJ just hiked to 1% — why did stocks rally instead of falling?
On June 16 the Bank of Japan raised its benchmark rate from 0.75% to 1%, yet the Nikkei surged higher after the decision rather than pulling back.
The yen weakened post-hike to roughly 160.6 per dollar. Chief Cabinet Secretary Minoru Kihara said the government stands ready to respond to excessive currency moves.
In plain terms = a rate hike is supposed to strengthen the currency and weigh on equities. The market read it differently: yen stays weak → Japanese exporters keep printing profits → stocks keep climbing. The exchange-rate signal overrode the interest-rate signal.
Oil at $75 — what does that have to do with Asian equities?
The U.S.–Iran interim peace deal signed by President Trump took effect on June 18. The prospect of a full reopening of the Strait of Hormuz pushed global crude to roughly $75 a barrel, the lowest since early March.
This means → cheaper oil is a double tailwind for Japan and Korea, both net energy importers: corporate costs fall, and the broader rise in global risk appetite channels capital into Asian equities.
Content is for reference only, not financial advice.