A category the media creates, not the exchange
Korean market coverage constantly refers to 테마주 — theme stocks. A theme is a story (HBM memory, nuclear power, defense exports, robotics) and the theme stocks are the companies mentioned alongside it. It is not an exchange classification, an index, or a sector code. It is a grouping that emerges from what the press writes about, and it can appear and fade within weeks.
Why it matters more here
Retail investors trade a large share of Korean volume, especially on KOSDAQ, and coverage moves quickly across a dense domestic media market. A single policy announcement or an overseas headline can pull a dozen small caps together in the same session. This is why Korean market reports so often describe a day by which themes moved rather than which sectors did.
How the lists on this site are built
We assign a theme when a headline contains its keywords, then count the listed companies named in those articles. No one picks the constituents by hand and there is no ranking of importance — the order you see is simply how many articles mentioned each company. Our theme pages show the count for the past seven days.
Being on a list is not a business fact
A company can appear because it was named once in passing, quoted as a competitor, or mentioned as a potential supplier. To find out whether the business is real, read the filings: supply contracts, capital spending, and the segment revenue table in the periodic report. The industry code the company registered with DART, shown on our industry pages, is a better guide to what it actually does.
What to check before believing a theme
Look for a filing behind the story — a contract, an investment decision, a clinical result — and then for it in revenue. If a company draws heavy coverage with nothing in its filings and no change in quarterly results, the catalyst may be the coverage itself. Watch for capital raising too: companies in a hot theme often issue new shares or convertible bonds while attention is high.
What this site will not tell you
We do not rank a theme leader, recommend constituents, or use price and volume data at all. A surge in article count means attention, not direction. The classification rules and their limits are described on our about page.
This is an explanation of rules and procedure, not investment advice. Rules reflect September 2026 and can change; check the filing and your broker before acting. Corrections: contact us.