Direct Answer
The HNX30 Index is a rule-based measurement of Hanoi blue-chip 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 HNX30 Index covers Hanoi blue-chip 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 name states a target of 30 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
Swoopr has not verified the weighting method for this index against HOSE/HNX's current methodology document, so none is stated here rather than guessed. The provider link below is authoritative.
What qualifies for inclusion
Stocks of companies listed on HNX, excluding those under control or trading suspension within three months. Selection takes the top 100 by average daily trading value over 12 months, then the top 70 by 12 month free float adjusted market cap, drops stocks with a median volume ratio below 0.02% in 6 of 12 months, and picks the 30 largest with no sector above 20% of the basket.
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
Stocks listed and traded on HNX for less than six months are excluded unless the index council approves a special exception.
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 every six months. Data are cut on the last trading day of March and September, the index council reviews in the second week of April and October, results are announced at least seven working days ahead, and changes take effect on the last trading day of April and October.
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
At each periodic review, normally 25 of the 30 current members are retained first, subject to turnover and liquidity tests, and any shortfall is filled from the Top70.
References
- HOSE/HNX: Hanoi Stock Exchange (HNX), HNX30 constituent selection criteria page, Chi so Top, as published 2026. Every rule described on this page is taken from this document.
Current HNX30 Index constituents
HOSE/HNX publishes and licenses the HNX30 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 HNX30 Index?
HOSE/HNX maintains the HNX30 Index and publishes the methodology document that defines its eligibility and weighting rules.
What does the HNX30 Index measure?
It measures Hanoi blue-chip 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 HNX30 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.