Not financial advice. This is a market-structure guide from Seoul, not a recommendation. The author holds none of the securities mentioned.
Nvidia posted its largest quarter ever after the US close on Wednesday, August 26 — data-center revenue alone of $89.0 billion, with next-quarter guidance of $108.0 billion (±2%). And the first major market to trade that number in cash was Seoul the next morning: on Thursday, August 27, the KOSPI closed up 1.54% at 6,912.37.
Which leaves a US reader with one question: “So how do I actually buy memory?”
There are three doors. And the three are not the same bet.
- The first door (EWY, the Korea ETF) and the second door (DRAM, the memory ETF) — opposite names — both buy Samsung Electronics and SK Hynix.
- The third door (Micron / MU) does not buy those two companies. It bets on the American challenger trying to take their place.
All three tickers say “memory.” Their holdings point to opposite sides.
🎩 What this means for EWY holders. If you hold EWY, roughly 41% of it is already these two companies (iShares, Aug 6). Add Micron on top and you have not “increased memory” — you have bought the competitor of the two companies you already own. The directions do not overlap.
The first two doors — opposite names, same insides
We took this apart last week: DRAM (the Roundhill Memory ETF), which wears the name “memory,” and EWY, which wears the name “Korea,” hold Samsung and SK Hynix at nearly the same weight. We laid that comparison side by side in part one.
Just the numbers again:
| Product | Samsung + SK Hynix | Measure · as of |
|---|---|---|
| EWY (iShares MSCI South Korea) | ~41% | Issuer-published NAV weight · 2026-08-06 |
| DRAM (Roundhill Memory ETF) | ~46–49% | Issuer fact sheet (6/30, 49.0%) / August vendor estimate (~46%) |
★ The takeaway is simple: both funds are close to half in those two companies. We do not push it further than that, because the two percentages are not measured the same way — EWY’s is the weight iShares publishes directly, while DRAM’s is adjusted for the swaps it uses to hold its positions. So we do not stack a precise “46 beats 41” on them. The exact arithmetic is in part one.
That is the first two doors. Now we open the third.
The third door — Micron is not “memory,” it is the other side
When a US reader searches “memory,” the ticker rising fastest lately is MU (Micron). US-listed, dollar-denominated, an American company. It looks like “a way to buy memory without Korea risk.”
But what buying Micron actually bets on only becomes visible when you look at the HBM (high-bandwidth memory) supply picture. HBM is the exact memory that sits on Nvidia’s AI chips.
From here on, note that these are market-research and press estimates, not figures the companies confirm (the suppliers do not officially confirm customer-by-customer volumes):
- SK Hynix leads HBM at ~62% (2025, industry estimate) and is reported to be set to supply about two-thirds of the HBM4 memory for Nvidia’s next-generation chips (the Rubin generation). Its DRAM, NAND and HBM for 2026 are reported to be sold out — again, that is reporting and estimate, not a company statement.
- Micron is estimated to have moved past Samsung into second place (5–20%, depending on the metric).
- Samsung sits third and is trying to rebound with HBM4.
So HBM is a share war, and the reigning champion of that war is Korean. Buying Micron is not a bet that “memory goes up” — it is a bet that the challenger takes the champion’s share. The direction is reversed.
That is why Micron does not sit in the same basket as the two Korean companies.
- EWY holds no Micron — it is a Korea index, so of course not.
- DRAM holds about 25% Micron — roughly half its Korean-two weight (~46–49%).
- And SK Hynix’s Nasdaq-listed ADR (SKHY) — a US-traded stand-in for the Seoul share — is yet another door. Why the Seoul share and the New York ADR drift apart in price we covered separately.
Buying “semiconductors” barely buys memory
One more misconception to clear: “Can’t I just buy a semiconductor ETF?”
| ETF | Micron weight | The two Korean names | As of |
|---|---|---|---|
| SOXX (iShares Semiconductor) | ~8% | Under 1% each, within disclosed holdings | 2026-08-13 |
Broad semiconductor ETFs like SOXX and SMH are mostly logic and equipment — Nvidia, AMD, Broadcom, TSMC. The world’s No. 1 and No. 2 DRAM companies each come in under 1% of a flagship semiconductor ETF, within the holdings the data provider discloses (meaning under 1% if present — not a claim that they are absent).
Why now — Korea traded Nvidia’s number first
There is a reason this structure is especially sharp today.
Nvidia reported after the US close on August 26 (about 16:20 ET). That instant is 5:20 a.m. on August 27 in Seoul — three hours and forty minutes before the Korea Exchange opens. So the first market in the world to price Nvidia’s data-center $89.0 billion and its $108.0 billion guidance into cash was Seoul on August 27. The KOSPI closed +1.54% (6,912.37) and Samsung Electronics closed +1.72% (₩266,000). The structure of Korea trading Nvidia first, we mapped here.
🎩 Question — so if Nvidia rises, do the two Korean companies automatically rise?
It is not that simple. Seoul’s August 27 gain also had the Bank of Korea’s rate hike (2.75% → 3.00%) and Jackson Hole (the Fed’s annual policy symposium) layered onto the same day — you cannot pin it on one factor. And the following Friday gave some of it back on AI-chip profit-taking (on an intraday, press basis). Nvidia’s strong print grows the “memory demand” pie, but who takes how much of that pie is decided by the HBM share war. In that war, the three doors stand on different sides.
So what do you actually look at — a map of the three doors
The doors in front of a US investor who wants memory exposure, and what each door actually gives you:
| Route | Samsung + SK Hynix | Micron | Character |
|---|---|---|---|
| EWY (Korea ETF) | ~41% | 0% | The two Korean names + ~80 Korean stocks |
| DRAM (memory ETF) | ~46–49% | ~25% | The two Korean names + global memory |
| SOXX / SMH (semi ETF) | Under 1% each | ~8% | Logic and equipment; thin on memory |
| MU (Micron, single stock) | 0% | 100% | The competitor of the two Korean companies |
| SKHY (SK Hynix ADR) | SK Hynix only | 0% | The champion, one name, direct |
One thing you can act on: open the holdings of the ETF you already own. iShares (EWY) and Roundhill (DRAM) both publish their holdings for free. Before you add Micron “to increase memory,” it helps to see which side you already stand on, and how much. (Not a buy suggestion — a checkable action.)
What this says about the Korean market
Line these three doors up and a fact about the Korean market comes into view that none of them shows alone.
To a US reader, “memory” looks like a sector you can buy. In practice it is a share war in which you pick a side, and the reigning champion of that war is two Korean companies. That is why EWY and DRAM both end up holding these two at close to half — more than half of the world’s HBM supply comes out of Seoul and Icheon (industry estimate). It is also why the third door, Micron, is a different object. It is not a bet on memory — it is a bet on Korea’s share shrinking.
🎩 Under the Gat. The ticker says “memory.” The holdings say “Korea.” And whoever picks Micron has, in fact, put money on “not Korea.” What you bought is told by the holdings, not the ticker — and those holdings are published for free.
FAQ
Q. Is Micron in EWY?
No. EWY tracks a Korea index (MSCI Korea 25/50), so Micron, a US company, is not a constituent. If you want Micron exposure, you choose among DRAM (~25%), SOXX (~8%), or MU directly.
Q. Does buying Micron mean buying “memory without Korea risk”?
The direction is different. HBM is a share war and the current No. 1 is SK Hynix (industry estimate ~62%). Buying Micron is a bet that the gap narrows — it is not the same bet as “memory goes up.”
Q. If Nvidia’s results are strong, do SK Hynix and Samsung go up too?
The pie grows. But Seoul’s August 27 gain also carried a rate hike and Jackson Hole, so it cannot be read as a single factor, and who captures how much is decided by HBM share.
Q. Which door is the most concentrated?
SKHY (the SK Hynix ADR) is a single name, so it is the most concentrated; DRAM is more crowded into the two Korean companies than EWY is (allowing for the measurement difference). EWY, with ~80 Korean stocks, is the most diversified.
Sources: iShares MSCI South Korea ETF (EWY) — official holdings CSV, 2026-08-06 (Samsung 21.13% · SK Hynix 20.25%) [primary] · Roundhill Memory ETF (DRAM) — issuer fact sheet, 2026-06-30 (Korean two 49.0% · Micron 25.81%) [primary, sourced in part one] · SOXX holdings — vendor (Finnhub), 2026-08-13 [secondary] · NVIDIA Q2 FY2027 results — NVIDIA Newsroom / GlobeNewswire, 2026-08-26 [company release] · HBM share and Nvidia supply — Astute Group · Counterpoint · TrendForce · Notebookcheck, 2026 [analyst/press estimate, not company-confirmed] · KOSPI and Samsung close, 2026-08-27 — Yahoo ^KS11 / 005930.KS, direct [primary] · Bank of Korea base rate, 2026-08-27, 3.00% — Korea Herald · Bloomberg [press].
Written by Mr.Gat — TheGatBull
Korean market coverage from a Seoul-metro-based operator who reads the filings in the original language. Every price on this site is the KRX regular-session close (15:30 Seoul); every figure states whether it came from a primary filing, the press, or our own calculation. Drafts are AI-assisted, then verified against the original Korean documents and edited by a human before publishing.
Found an error? Tell us — corrections get priority. How we work →
This is a market-structure guide, not investment advice. Nvidia figures are in US dollars from the company’s release; Korean prices are in ₩ (won) at the KRX regular-session 15:30 Seoul close (2026-08-27). ETF weights are issuer- or vendor-published as of the dates shown.