Direct Answer
The FTSE TWSE Taiwan 50 Index is a rule-based measurement of top 50 Taiwanese equities, maintained by TWSE/FTSE Russell. 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 FTSE TWSE Taiwan 50 Index covers top 50 Taiwanese equities, within the Taiwan market. TWSE/FTSE Russell 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
Market capitalisation adjusted for free float and foreign ownership limits. A separate 30% Capped variant holds the same constituents with any one company capped at 30% of the index weight each quarter. Values are calculated in New Taiwan dollars in real time.
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 50 largest companies by full market value among stocks listed on the Taiwan Stock Exchange. Full delivery stocks and investment trusts are ineligible. A free float of 5% or below is excluded, and a float above 5% up to 15% qualifies only with full market cap above USD 2.5 billion.
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.
How long a listing must exist first
New issues and newly eligible securities need a trading record of at least 20 days and a turnover of 0.050% of shares. An IPO that would rank 20th or higher by full market cap can fast enter after its fifth trading day with no liquidity test.
A seasoning rule is why a large new listing does not appear in an index the week it starts trading. It is a deliberate lag, and it means an index can under-represent a fast-growing part of the market for months at a time.
When the membership is revised
Quarterly reviews in March, June, September and December, using data from the Monday four weeks before the effective date, with changes applied after the close on the third Friday. The annual liquidity test happens with the March review.
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
The constituent count is fixed. A company is inserted only if it rises to 40th or above and deleted only if it falls to 61st or below, and a deleted member normally moves into the Mid-Cap 100.
References
- TWSE/FTSE Russell: FTSE Russell FTSE TWSE Taiwan Index Series Ground Rules, as published 2026. Every rule described on this page is taken from this document.
Current FTSE TWSE Taiwan 50 Index constituents
TWSE/FTSE Russell publishes and licenses the FTSE TWSE Taiwan 50 Index 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 FTSE TWSE Taiwan 50 Index?
TWSE/FTSE Russell maintains the FTSE TWSE Taiwan 50 Index and publishes the methodology document that defines its eligibility and weighting rules.
What does the FTSE TWSE Taiwan 50 Index measure?
It measures top 50 Taiwanese equities. 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 FTSE TWSE Taiwan 50 Index constituents?
TWSE/FTSE Russell publishes the current constituent list. Swoopr does not republish it, because index providers license constituent data and Swoopr holds no such licence.