Direct Answer
The IATX (Immobilien-ATX) is a sector benchmark tracking the performance of real estate companies listed on Wiener Borse. Administered by Wiener Borse AG, it is free-float-adjusted and market-capitalisation-weighted, providing a focused measure of the Austrian-listed real estate equity segment rather than the full market.
What this index covers
The IATX (Immobilien-ATX) covers the Austria equity market through the Vienna Stock Exchange (Wiener Borse). Wiener Borse AG 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: Real estate companies listed on Wiener Borse that meet the eligibility criteria set out in the Wiener Borse published methodology for the IATX.
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, consistent with the broader ATX index family approach published by Wiener Borse AG.
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 IATX (Immobilien-ATX), the relevant market is the Vienna Stock Exchange (Wiener Borse) and the administrator is Wiener Borse AG. Per the published Wiener Borse AG methodology (verification date: August 31, 2026), the eligible universe is defined as: Real estate companies listed on Wiener Borse that meet the eligibility criteria set out in the Wiener Borse published methodology for the IATX.
Reconstitution schedule
Reviewed on the same quarterly schedule as the ATX family. Eligibility is assessed against the sector classification and minimum size or liquidity thresholds in the published methodology.
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
Reference for real estate sector exposure within Austria; used by sector-focused mandates and structured products benchmarking Austrian real estate equities.
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 IATX (Immobilien-ATX) is most often compared with:
- ATX: the main Austrian benchmark covering all sectors; the IATX is limited to real estate.
- ATX Prime: broadest Austrian all-sector index; the IATX segments out the real estate component.
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
- Wiener Borse: IATX Index Overview, as published per the provider's methodology page. All methodology claims on this page are derived from this source.
Current IATX (Immobilien-ATX) constituents
Wiener Borse AG publishes and licenses the IATX (Immobilien-ATX) 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
What does IATX stand for?
IATX stands for Immobilien-ATX. "Immobilien" is the German word for real estate. The index tracks the Austrian-listed real estate equity sector.
Who administers the IATX?
Wiener Borse AG administers the IATX under its published index governance framework.
How is the IATX different from the ATX?
The ATX is a broad, multi-sector benchmark of the most liquid Austrian shares. The IATX is a sector index limited to real estate companies, providing concentrated exposure to that segment.
How often is the IATX reviewed?
On the same quarterly schedule as the ATX family: March, June, September and December.
Where can I find current IATX data?
Wiener Borse AG publishes index data including constituent information on its official index overview page.