Direct Answer
The OMX Tallinn index covers all shares listed on Nasdaq Tallinn (the Estonian stock exchange) that meet eligibility criteria in the published Nasdaq OMX Baltic Index Methodology. Administered by Nasdaq Nordic and Baltic Indexes, it is the national all-share benchmark for Estonian-listed equities.
What this index covers
The OMX Tallinn covers the Estonia equity market through the Nasdaq Tallinn. Nasdaq Nordic and Baltic Indexes defines which securities are eligible, how they are selected from that pool and how much each contributes to the published number.
The eligible universe is: All shares listed on Nasdaq Tallinn satisfying the free-float and eligibility criteria in the published Nasdaq OMX Baltic Index Methodology.
Understanding the eligible universe is the most important step in understanding what an index measures. An index that selects by listing venue will behave differently from one that selects by company domicile, and a sector index will have very different risk characteristics from a broad market measure even if they share some constituents.
How constituents are weighted
Free-float-adjusted market-capitalisation weighting, per the Nasdaq OMX published methodology.
Weighting is the mechanism that translates a list of companies into a single number. Free-float-adjusted market-capitalisation weighting is the most common method: larger companies contribute more to the index level than smaller ones, and the free-float adjustment excludes shares that are not available to public investors (such as government-held strategic stakes or closely-held founder shares). This makes the index level reflect the actual investable market rather than total market size.
Eligible universe and eligibility rules
Eligibility rules determine which companies can be included at a review and which must exit. The key dimensions to verify are: which exchange or market segment is in scope; whether domicile or listing venue determines eligibility; the minimum free-float threshold; the liquidity screen; and whether there are sector restrictions.
For the OMX Tallinn, the relevant market is the Nasdaq Tallinn and the administrator is Nasdaq Nordic and Baltic Indexes. Per the published Nasdaq Nordic and Baltic Indexes methodology (verification date: August 31, 2026), the eligible universe is defined as: All shares listed on Nasdaq Tallinn satisfying the free-float and eligibility criteria in the published Nasdaq OMX Baltic Index Methodology.
Reconstitution schedule
Semi-annual, aligned with the broader OMX Baltic index family review schedule.
Reconstitution is the date on which the index changes shape by design rather than by price. Passive funds tracking the index must trade toward the new membership list, which creates predictable order flow around the review date. Active managers often position around reconstitution events to capture or avoid that flow.
How investors use this index
National Estonian equity benchmark; reference for country-specific Baltic exposure and cross-Baltic comparison against OMX Riga and OMX Vilnius.
For any index, three uses are distinct: as a performance benchmark (measuring how well a portfolio did relative to the market), as a product underlying (an ETF or structured product replicating the index), and as a research reference (tracking market-cap, sector weights or concentration over time). The same index can serve all three purposes, but the choice of which to use depends on the investment mandate and the specific question being answered.
Comparisons with related indexes
The OMX Tallinn is most often compared with:
- OMX Baltic Benchmark: pan-Baltic; OMX Tallinn is Estonia only.
- OMX Baltic 10: the ten most liquid Baltic shares across all three countries; OMX Tallinn covers all Estonian listings.
- OMX Riga: the Latvian equivalent; structurally parallel but measuring a different national market.
When switching from one benchmark to another, the practical question is what changes in coverage: does the alternative add smaller companies, exclude a sector, change the weighting method or extend to a different currency? Each of these changes alters what the index can tell you about market performance.
References
- Nasdaq: OMX Baltic Index Family, as published per the provider's methodology page. All methodology claims on this page are derived from this source.
Current OMX Tallinn constituents
Nasdaq Nordic and Baltic Indexes publishes and licenses the OMX Tallinn 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.
- European Stock Market 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 administers the OMX Tallinn?
Nasdaq Nordic and Baltic Indexes administers the OMX Tallinn under the published Nasdaq OMX Baltic Index Methodology.
What market does the OMX Tallinn cover?
Nasdaq Tallinn, the regulated stock exchange in Estonia. The index includes all shares meeting the minimum free-float and eligibility criteria.
What currency is the OMX Tallinn calculated in?
The OMX Tallinn is calculated in euros, consistent with the OMX Baltic family, as Estonian exchange securities are denominated in EUR.
How does OMX Tallinn differ from the OMX Baltic 10?
The OMX Baltic 10 selects the ten most liquid shares across all three Baltic exchanges. OMX Tallinn covers all qualifying Estonian listings, including smaller companies outside the Baltic 10.
Where can I see current OMX Tallinn data?
Nasdaq publishes OMX Tallinn index information on its official pages. Swoopr links to the provider rather than reproducing licensed constituent data.