Direct Answer
The HNX Index is a rule-based measurement of broad Hanoi equity benchmark, maintained by HOSE/HNX. 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 HNX Index covers broad Hanoi equity benchmark, within the Vietnam market. HOSE/HNX 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
A stock needs a free float of at least 5% to be included. The detailed construction and weighting rules sit in HNX's separate index management rules.
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
All stocks of companies listed on HNX with a free float ratio of 5% or more are selected. A newly listed stock is added automatically, and a stock that is delisted, suspended, acquired or judged by the index council to fail the criteria is removed.
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
The composition of stocks used in the index is reviewed quarterly, in line with the free float adjustment cycle in the index rules. A suspended stock may stay in the index for up to 10 working days before it is normally removed at its last traded price.
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
There is no ranking or fixed count: every listed stock above the 5% free float floor is in, so the basket changes with new listings and delistings, and a company returning after a rename, merger or split with a non-member is not treated as a new stock.
References
- HOSE/HNX: Hanoi Stock Exchange, Composite index selection criteria and index calculation method (HNX Index rules), as published 2026. Every rule described on this page is taken from this document.
Current HNX Index constituents
HOSE/HNX publishes and licenses the HNX 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.
- 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 HNX Index?
HOSE/HNX maintains the HNX Index and publishes the methodology document that defines its eligibility and weighting rules.
What does the HNX Index measure?
It measures broad Hanoi 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 HNX Index constituents?
HOSE/HNX publishes the current constituent list. Swoopr does not republish it, because index providers license constituent data and Swoopr holds no such licence.