Not financial advice. TheGatBull does not provide investment advice.
Two stocks sit under the same label — “Korean batteries.” This year one of them doubled and the other barely moved. If you own EWY, you own both, in the ratio someone else picked.
The short answer
As of the September 18 Seoul close, Samsung SDI (KRX: 006400) is up 100.7% for the year. LG Energy Solution (KRX: 373220) is down 1.2% over the same stretch. The KOSPI — Korea’s main stock index — rose 63.6%. So one of these two beat a roaring index by a wide margin, and the other sat out the whole rally.
The gap between them is 102 percentage points. Both figures are won-denominated KRX closes measured from the same December 30, 2025 anchor, so subtracting them is fair.
One thing this article is not: a case for either stock. A number that already doubled is not a recommendation, and a flat one is not a bargain. What the split is good for is showing you something about how this market is behaving — which is where we are going.
What this means for EWY holders
Inside EWY — the iShares MSCI South Korea ETF — Samsung SDI is 1.21% (its 12th-largest holding) and LG Energy Solution is 0.76% (23rd), for 1.97% combined (iShares holdings, as of September 11). Your “Korean battery” exposure is already tilted about 1.6 to 1 toward the one that doubled — not because you chose that, but because index weights follow market value.
Way 1 — the lumped view: “Korean batteries” is one trade
Screeners, thematic lists and sector tabs put these two companies in the same box. One checkbox: Korean battery stocks. Korean market shorthand does the same thing, ranking a theme’s names in a single lineage under a daejangju — the leading stock the rest of the group is supposed to follow.
The logic is not stupid. Same industry, same country risk, same currency, same investor conversation. Things that share that much usually move together.
And the lumping is not only a retail habit — it is built into the plumbing. Index and screener classifications sort companies by what they make, because that is the attribute that stays stable long enough to file. Demand is the thing that actually moves the stock, and demand is not a field in the classification. So a bucket can stay accurate as a description of the product while becoming useless as a description of the trade.
Who they are, in one line each:
- LG Energy Solution — the LG group’s battery cell maker, listed in 2022, running several joint-venture plants with automakers in the US. Closed at ₩364,000 (roughly $270).
- Samsung SDI — the Samsung group’s battery and electronic-materials company. Closed at ₩541,000 (roughly $402).
Dollar figures use ₩1,345.9 per dollar, the September 11 Seoul close — our latest confirmed rate. Treat them as approximate.
For a US frame of reference, the closest thing on the board is Panasonic (OTC: PCRFY) — a non-US company with a battery-cell business, reachable over the counter. Not a perfect parallel: Panasonic is a diversified conglomerate with a battery arm, while both Korean names are far more concentrated in batteries.
If Way 1 is right, the two stocks should have had a similar year.
Way 2 — the data view: there was no sector this year
| Dec 30, 2025 close | Sept 18, 2026 close | Year to date | |
|---|---|---|---|
| Samsung SDI | ₩269,500 | ₩541,000 | +100.7% |
| LG Energy Solution | ₩368,500 | ₩364,000 | −1.2% |
| KOSPI | 4,214.17 | 6,894.23 | +63.6% |
| KOSDAQ | 925.47 | 827.12 | −10.6% |
All KRX regular-session closes, in won. US-listed comparisons are kept out of this table on purpose — different currency, different trading calendar.
It is not just the year-end scoreboard. Their paths do not even overlap. Each stock’s highest close of the past year lands in a different season:
- LG Energy Solution peaked last autumn — a 52-week closing high of ₩514,000 on October 29, 2025. It sits 29.2% below that today, having bounced off a July low.
- Samsung SDI peaked this spring — a 52-week closing high of ₩712,000 on April 29, 2026. It sits 24.0% below that today. Which is the part the headline hides: doubling for the year and being down about a quarter from the high are both true of the same stock.
One peaked last year, the other peaked this year. Whatever “same sector, same direction” is supposed to mean, the 2026 data does not show it.
Friday made the same point in miniature. The KOSPI jumped 2.66% — and both battery names opened higher and then sold off through the Seoul session. (Gap = open vs. prior close, what attached overnight. Own session = close vs. open, what Seoul did between 9:00 and 3:30.)
| Gap | Own session | Day | |
|---|---|---|---|
| KOSPI | +2.54% | +0.12% | +2.66% |
| LG Energy Solution | +1.51% | −1.75% | −0.27% |
| Samsung SDI | +2.04% | −1.64% | +0.37% |
On a day the index gained 2.66%, neither battery stock came along. We walked through this gap-versus-session split in the piece on the day KOSPI fell while its own session rose.
🎩 Under the Gat — Screeners sell you “Korean batteries” as one checkbox. Seoul priced them as two different countries this year. A label is a filing convenience. Prices are under no obligation to respect it.
What we can and cannot tell you about the split
Here the confidence grades change, and it matters.
Confirmed, from KRX closing prices: the divergence itself. +100.7% against −1.2%, the mismatched highs, Friday’s shared session weakness. Those are arithmetic on public closes.
Not confirmed: the reason. Two narratives circulate — that LG Energy Solution is carrying slower EV demand, US tariffs and automaker order adjustments; that Samsung SDI is carrying ESS (energy storage systems — the grid- and data-center-scale battery installations) and AI data-center power demand. Both are plausible. Both are press narratives we have not confirmed from a primary source, and this article does not assert either as the cause. Until the order books say so in a filing, they are the market’s interpretation, not a finding.
What we would watch instead, in order of how directly it would settle the question:
- Both companies’ third-quarter results — specifically whether the order backlog actually splits between EV and non-EV (ESS) demand the way the narratives claim.
- Supply-contract filings on DART, Korea’s disclosure system — which kind of contract lands on which company.
- US tariff follow-through — whether battery cells and materials end up in scope.
Worth naming what would make us drop the narratives rather than confirm them. If the third-quarter backlogs show a similar demand mix at both companies, then the story that one is riding storage while the other waits on electric vehicles is wrong, and the split needs a different explanation — margins, contract terms, a customer concentration nobody is looking at. We would rather publish that correction than defend a tidy story. The point of writing down the test in advance is that it can fail.
What this says about the Korean market
Korea’s 2026 rally has run alongside a surge in semiconductor names: EWY’s top two holdings alone — SK Hynix, a memory-chip maker, and Samsung Electronics — are 46.1% of the fund. What happened in the shade of that is this article’s actual subject: the word “sector” is coming apart in this market.
At the index level, MSCI’s August review changed what EWY holds (what changed inside EWY in August). At the stock level, the same “battery” bucket produced a winner and a flat line. The thing that decided returns in Korea this year was not the country and not the sector. It was which demand you were attached to.
The practical translation for a US investor: buying “Korea exposure” through the index is, in effect, a semiconductor bet with a long tail attached. And if you want battery exposure specifically, the label will not choose for you — you have to pick which battery. A 63.6% index year containing a −1.2% holding is not a malfunction; that is what index investing is. We saw the same structure in Kia sitting out Korea’s big year.
🎩 Under the Gat — Here is the fact you cannot see without these two companies: Korea’s 2026 rally was not a story about a market. It was a story about demand. And chasing the one that is up 100% is no more justified by this data than bargain-hunting the one that is flat — this is a view, not advice.
How a US investor reaches these two
In order of how easily you get there:
- Already owned: EWY holds both — 1.97% combined (SDI 1.21%, LGES 0.76%, as of September 11). Small, but you have the exposure whether or not you wanted it.
- Directly, in the US: as far as we could confirm, LG Energy Solution has no US listing. An over-the-counter symbol for Samsung SDI is sometimes cited, but we could not verify its existence or liquidity, so we are not printing it as a route.
- Directly, on the KRX: brokers offering Korean market access can buy 373220 and 006400 in won directly. Availability varies by broker.
“You can’t buy it from the US” is not a dead end. It likely also means less American money has arrived — a less crowded trade.
The takeaway
In 2026, the thing called “the Korean battery sector” did not exist in the data. What existed were two companies having opposite years: +100.7% and −1.2%, under one label, inside one ETF, at weights nobody asked you about. Before you buy the name of a bucket, look at what is pulling apart inside it. That is how you read a country that trades as an index.
FAQ
Is Samsung SDI in EWY?
Yes — 1.21% of the fund, its 12th-largest holding (iShares holdings, as of September 11, 2026). LG Energy Solution is also in EWY, at 0.76% (23rd). Together they are about 1.97% of the ETF.
Can US investors buy LG Energy Solution stock?
Not on a US exchange, as far as we could confirm — there is no US listing or ADR we could verify. The practical routes are EWY (0.76% exposure) or buying 373220 directly on the KRX through a broker with Korean market access.
Why did Samsung SDI stock double in 2026?
The doubling is confirmed by KRX closing prices: +100.7% year to date through September 18. The why is not. Narratives about ESS and AI data-center demand are press-reported and we have not confirmed them from a primary source — the place to check is the order-book split in both companies’ third-quarter filings.
Did Korean battery stocks rise with the 2026 KOSPI rally?
Not as a group. The KOSPI rose 63.6% year to date; Samsung SDI doubled while LG Energy Solution finished the same stretch down 1.2%. The two halves of the “sector” went opposite directions.
If Samsung SDI doubled, is it at a high?
No. Its highest close of the past year was ₩712,000 on April 29, 2026, and it currently sits 24.0% below that. Up 100.7% year to date and down 24.0% from the high are both true of the same stock — they just use different starting points.
What is a daejangju?
Korean market shorthand for the leading stock of a theme or sector — the name retail investors treat as setting the direction for the rest of the group. The 2026 battery split is a case where the group did not follow anything.
Sources
- Closing prices and year-to-date figures (373220.KS, 006400.KS, ^KS11, ^KQ11): market data queried directly — KRW · KRX regular session (3:30 PM KST) · Asia/Seoul vendor tags, September 18, 2026. Year-to-date is measured from the December 30, 2025 close, this site’s standard anchor. Every percentage re-verified against the underlying closes.
- 52-week closing highs: LG Energy Solution ₩514,000 (October 29, 2025); Samsung SDI ₩712,000 (April 29, 2026) — each dated, each measured on closes.
- EWY weights: iShares MSCI South Korea ETF holdings disclosure, as of September 11, 2026.
- Won–dollar conversion: ₩1,345.9 (Seoul 3:30 PM close, September 11, 2026 — latest confirmed). Used for the two approximate dollar figures only.
- Not claimed: the causes of the divergence (EV demand, tariffs, ESS, AI data-center demand are press narratives, not confirmed from primary sources); the existence or liquidity of any over-the-counter US symbol for either company.
Not financial advice. This article is for information only. TheGatBull and its author hold no position in the securities mentioned unless disclosed. Confidence labels are as of publication.