Direct Answer
The ASE20 is a rule-based measurement of top 20 companies listed on the Amman Stock Exchange by market capitalisation, maintained by Amman Stock 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 ASE20 covers top 20 companies listed on the Amman Stock Exchange by market capitalisation, within the Jordan market. Amman Stock 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 20 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
Price index weighted by the market capitalization of free float shares. Each company's value is its listed shares times the last close times a factor built from its free float ratio (listed shares less holdings of directors, investors above 5% and any government ownership) and an adjustment for capping. The factor is changed at each index re-balancing.
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.
When the membership is revised
The free float and capping factors change at each index re-balancing, and the constituents page read is the sample for the fourth quarter of 2026.
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 weight of any single company is capped at 10% of the index, and the exchange cuts that company's factor whenever its weight would exceed 10% of index market capitalization.
References
- Amman Stock Exchange: Amman Stock Exchange, Constituents ASE20 and ASETR, as published 2026. Every rule described on this page is taken from this document.
Current ASE20 constituents
Amman Stock Exchange publishes and licenses the ASE20 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 ASE20?
Amman Stock Exchange maintains the ASE20 and publishes the methodology document that defines its eligibility and weighting rules.
What does the ASE20 measure?
It measures top 20 companies listed on the Amman Stock Exchange by market capitalisation. 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 ASE20 constituents?
Amman Stock Exchange publishes the current constituent list. Swoopr does not republish it, because index providers license constituent data and Swoopr holds no such licence.