Direct Answer
The KOSPI 50 is a rule-based measurement of Korean large-cap equity benchmark, maintained by Korea Exchange. Like every index it owns nothing: it is a number produced by applying a published weighting formula to a selected list of companies, revised on a schedule the provider sets.
What this index covers
The KOSPI 50 covers Korean large-cap equity benchmark, within the South Korea market. Korea Exchange defines which securities are eligible, how they are selected from that pool, and how much each one contributes to the published number.
The name states a target of 50 companies. A target is not a guarantee of the exact count on any given day: corporate actions, dual share classes and pending additions all move the real number around it.
How constituents are weighted
Float adjusted market capitalisation weighted with a 30% cap on individual constituents, calculated every 10 seconds, with a base value of 1,000 at January 4, 2000. Capping factors are set on the trading day after the last trading day of the June and December KOSPI 200 futures delivery month.
The weighting method is the single biggest driver of how an index behaves. Two indexes covering the same market can diverge for years purely because they weight differently, which is why comparing index levels without knowing the method tells you very little.
What qualifies for inclusion
The universe is the KOSPI 200 constituents as selected at the June and December rebalancing. The top 50 by average daily market capitalisation are chosen. Existing constituents within 120% of the current constituent count are retained, while a new addition must rank within 80% of it.
Eligibility rules are the part of an index most readers never look at and the part that decides what it can possibly measure. A screen that excludes a whole sector, or admits only one listing venue, shapes the result far more than any day of trading does.
When the membership is revised
Reconstituted twice a year, effective the trading day after the last trading day of the June and December KOSPI 200 futures delivery month. The largest 10 remaining stocks by average daily market capitalisation form the replacement pool for removals between rebalancings.
Reconstitution is the one date an index changes shape by design rather than by price. Funds tracking it have to trade toward the new membership, which is why the schedule matters to anyone holding the tracker rather than only to the provider.
The rule that surprises people
If a constituent spins off a company, only the parent company stays in the index and the spun off company is not added.
References
- Korea Exchange: Korea Exchange, KOSPI 100 and KOSPI 50 Indices Methodology, as published 2020. Every rule described on this page is taken from this document.
Current KOSPI 50 constituents
Korea Exchange publishes and licenses the KOSPI 50 constituent list. Swoopr does not republish it here. The provider's own page is the authoritative source for current membership and weights.
Related reading
- All stock market indexes: how indexes are built, weighted and revised.
- Asia-Pacific indexes: others covering the same region.
- Index concentration: measuring how much of an index sits in its largest holdings.
- Index rebalancing and inclusion effects: what happens to a stock when index membership changes.
Frequently Asked Questions
Who maintains the KOSPI 50?
Korea Exchange maintains the KOSPI 50 and publishes the methodology document that defines its eligibility and weighting rules.
What does the KOSPI 50 measure?
It measures Korean large-cap equity benchmark. The index is a calculated number applying a weighting formula to a selected list of companies, and it holds nothing itself.
Where can I see the current KOSPI 50 constituents?
Korea Exchange publishes the current constituent list. Swoopr does not republish it, because index providers license constituent data and Swoopr holds no such licence.