Direct Answer
The FTSE/JSE Mid Cap is a rule-based measurement of mid-cap companies listed on the Johannesburg Stock Exchange, maintained by FTSE Russell/JSE. 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/JSE Mid Cap covers mid-cap companies listed on the Johannesburg Stock Exchange, within the South Africa market. FTSE Russell/JSE 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
Investable market capitalisation: price times shares in issue times a free float factor. Since the 18 March 2024 harmonisation of the headline series, free float follows the SWIX basis (shares on the South African share register).
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
Mid Cap holds the band between 85% and 96% of the full market value of eligible main board ordinary shares, between the Large Cap and Small Cap bands. Each company needs a global free float above 5%, and a new security must turn over 0.5% of its shares in issue, after free float, in at least 10 of the prior 12 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.
When the membership is revised
Reviewed semi-annually in March and September with changes after the close on the third Friday. Buffers apply: a Mid Cap member moves up only when it ranks within the top 83% and moves down to Small Cap only below 97% of full market value.
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 size bands are measured on full market value before any free float adjustment, so index weights, which use investable value, can differ widely from each band's share of the market.
References
- FTSE Russell/JSE: FTSE Russell and JSE, FTSE/JSE Africa Index Series Ground Rules v9.3, as published 2026. Every rule described on this page is taken from this document.
Current FTSE/JSE Mid Cap constituents
FTSE Russell/JSE publishes and licenses the FTSE/JSE Mid Cap 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.
- Emerging Markets 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/JSE Mid Cap?
FTSE Russell/JSE maintains the FTSE/JSE Mid Cap and publishes the methodology document that defines its eligibility and weighting rules.
What does the FTSE/JSE Mid Cap measure?
It measures mid-cap companies listed on the Johannesburg Stock Exchange. 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/JSE Mid Cap constituents?
FTSE Russell/JSE publishes the current constituent list. Swoopr does not republish it, because index providers license constituent data and Swoopr holds no such licence.