Buying "Korea" through an index product is not buying 2,653 companies in any meaningful proportion. It is buying a concentrated position in about ten of them, with a very long tail attached for decoration.
1. Where the weight sits
Total market value is roughly US$4.0tn. Fifty companies — 1.9% of the listings — hold three-quarters of it. The bottom half of the market, 1,326 companies, sums to 1.1%. The median listed company is worth ₩100.8bn, about US$71m.
2. Consequences for index exposure
Korea's headline indices are capitalisation-weighted, so index moves are close to a scoreboard for the largest names — in practice, semiconductors above all. An investor who buys a broad Korea ETF expecting diversified exposure to the Korean economy is mostly taking a position in the memory cycle.
This also explains a complaint you hear constantly from domestic retail investors: the index rises and their portfolio does not. Both statements are usually true at the same time, because the index and the median stock are barely related.
If you want exposure to the rest of the market, cap-weighted products will not give it to you. Equal-weight, mid/small-cap or sector products are different instruments with different risks — see how Korean ETF costs and structures work.
3. Consequences for screening
Valuation norms differ sharply by size, so a single market-wide threshold sorts by market cap as much as by value:
| Market cap band | Companies | Median P/E | Median P/B |
|---|---|---|---|
| Above ₩1tn (~US$706m) | 305 | 24.7x | 1.99x |
| ₩300bn–1tn | 379 | 14.4x | 1.35x |
| ₩100–300bn | 645 | 12.0x | 0.97x |
| Below ₩100bn (~US$71m) | 1,324 | 12.1x | 0.68x |
Large caps carry roughly double the P/B of the smallest band. Some of that is quality and liquidity; some is index-driven demand. Either way, applying a "P/B below 1x" screen to the whole market returns mostly micro caps — which is a size decision disguised as a value decision.
4. The practical filter
Before any multiple, check traded value, not market cap. A company worth US$70m may trade a few hundred thousand dollars a day, at which point position sizing, not valuation, is the binding constraint. Also check the free float: where founding families and affiliates hold large stakes, the shares actually available are a fraction of the market cap.
Key figures
- ₩5,730tn (~US$4.0tn) total; top 10 = 56.6%; top 50 = 76.5%.
- Bottom 1,326 companies combined = 1.1%; median market cap US$71m.
- Median P/B runs 1.99x (large) to 0.68x (small) — size drives multiples.
- Cap-weighted Korea exposure is concentrated by construction.
This page organises publicly available data for reference only. It is not investment advice and contains no buy/sell recommendations, target prices, or ratings. Any company named is an example used to explain the data, not a suggestion. Verify figures against the original filings before acting on anything.