Direct Answer
The FTSE ST Mid Cap Index is a rule-based measurement of Singapore mid-cap equity benchmark, maintained by FTSE Russell/SGX. 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 ST Mid Cap Index covers Singapore mid-cap equity benchmark, within the Singapore market. FTSE Russell/SGX defines which securities are eligible, how they are selected from that pool, and how much each one contributes to the published number.
The index name does not state a fixed company count, so the number of constituents follows the eligibility rules rather than a target.
How constituents are weighted
Free float adjusted market capitalisation weighting using investability weights, calculated in Singapore dollars. Foreign ownership restrictions are not applied to constituents of the series.
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
A size band of the All-Share Index. Companies are ranked by full market capitalisation and a non-member enters if it ranks below the top 68% but within the top 86% of the index universe. The same free float, voting rights and investment trust exclusions as the rest of the series apply.
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
Liquidity is tested each March and September, and new issues need at least 20 trading days of record before being tested. A large IPO can fast enter the Large and Mid Cap group after its fifth trading day, otherwise it waits for the next review.
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
Reviewed semi-annually in March and September, with a quarterly review in June and December. The review uses data from the Monday four weeks before the effective date, and changes apply after the close on the third Friday of the review month.
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
Bands are set by cumulative market capitalisation, not a fixed company count. An existing Mid Cap member stays while ranked between 68% and 92% of the index universe, moving up only if it rises into the top 68%, down to Small Cap if it ranks below 92% but within 101%, and to Fledgling below 101%.
References
- FTSE Russell/SGX: FTSE Russell FTSE ST Index Series Ground Rules, as published 2026. Every rule described on this page is taken from this document.
Current FTSE ST Mid Cap Index constituents
FTSE Russell/SGX publishes and licenses the FTSE ST Mid Cap 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 ST Mid Cap Index?
FTSE Russell/SGX maintains the FTSE ST Mid Cap Index and publishes the methodology document that defines its eligibility and weighting rules.
What does the FTSE ST Mid Cap Index measure?
It measures Singapore mid-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 FTSE ST Mid Cap Index constituents?
FTSE Russell/SGX publishes the current constituent list. Swoopr does not republish it, because index providers license constituent data and Swoopr holds no such licence.