Direct Answer
The FTSE/ATHEX Mid Cap is a rule-based measurement of Greek mid-cap equity benchmark, maintained by FTSE Russell/Athens 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 FTSE/ATHEX Mid Cap covers Greek mid-cap equity benchmark, within the Greece market. FTSE Russell/Athens Exchange 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
Constituents are weighted by price times shares in issue times an investability (free float) weighting factor, with a capping factor term in the index formula. Companies with a free float of 15% or below are not eligible, and float above 15% is rounded up to the next whole percentage.
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 20 securities that rank immediately after the 25 FTSE/ATHEX Large Cap members by full market capitalization, among ordinary shares on the ATHEX main market that pass the investability screens. They must trade continuously, not trade by call auction, turn over at least 20% of free float shares a year, and trade on at least half the business days in each of the last six months.
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
A security needs a minimum trading record of 30 working days since the start of official non conditional trading. There are no fast entry rules for new issues to the Mid Cap index, so a new issue 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 semiannually using data for April and October, with market capitalization averaged over the last month. Changes are made after the close on the third Friday of June and December. A reserve list of five names is published and used to fill vacancies until the next 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
Ranking uses full market capitalization before free float adjustment. A non member enters at rank 35 or above and a member leaves only at rank 56 or below, and a security dropped from the Large Cap drops in automatically if it ranks above the lowest Mid Cap member.
References
- FTSE Russell/Athens Exchange: FTSE Russell with Athens Exchange, Ground Rules for the FTSE/ATHEX Index Series, version 8.8, July 2025, as published 2025. Every rule described on this page is taken from this document.
Current FTSE/ATHEX Mid Cap constituents
FTSE Russell/Athens Exchange publishes and licenses the FTSE/ATHEX Mid Cap constituent list. Swoopr does not republish it here. The provider's own page is the authoritative source for current membership and weights.
FTSE Russell/Athens Exchange: official FTSE/ATHEX Mid Cap page
Related reading
- All stock market indexes: how indexes are built, weighted and revised.
- Europe 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/ATHEX Mid Cap?
FTSE Russell/Athens Exchange maintains the FTSE/ATHEX Mid Cap and publishes the methodology document that defines its eligibility and weighting rules.
What does the FTSE/ATHEX Mid Cap measure?
It measures Greek 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/ATHEX Mid Cap constituents?
FTSE Russell/Athens Exchange publishes the current constituent list. Swoopr does not republish it, because index providers license constituent data and Swoopr holds no such licence.