--- title: "WIG30: Methodology" description: "WIG30 is maintained by GPW Benchmark and covers Polish blue-chip equity benchmark. How the index selects and weights its constituents, and what it measures." canonical: https://www.getswoopr.com/stocks/indexes/wig30/ source: "Swoopr Investment: https://www.getswoopr.com" --- # WIG30: What It Measures and How It Is Built ## Direct Answer > The WIG30 is a rule-based measurement of Polish blue-chip equity benchmark, maintained by GPW Benchmark. 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 WIG30 covers Polish blue-chip equity benchmark, within the Poland market. GPW Benchmark 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 Weighted by free float shares times price. A single company is reduced proportionally when it exceeds 10% of the index value, a tighter limit than the 15% used for WIG20. WIG30 is a price index, and WIG30TR is the total return version. 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 30 large and liquid companies from the GPW Main List taken from the same joint ranking as WIG20, mWIG40 and sWIG80, with a Monthly Turnover Ratio liquidity test whose level is the same value as for WIG20. At most seven companies may come from a single exchange sector. Base criteria for every GPW exchange index: free float above 10%, free float value above 1 million euros, at least one trade in the last three months, no special marking such as bankruptcy, and no alert list or lower liquidity segment. 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 An IPO is added between reviews if its free float capitalization at the IPO date is at least 5% of the free float capitalization of all WIG30 companies, and the lowest ranked member leaves. Without that, a new company waits for the next quarterly adjustment or annual revision. 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 Selected from rankings four weeks before the third Friday of March, June, September and December, effective after the session on that Friday with two weeks of notice. March is the annual revision and the other months are quarterly adjustments. 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 sector limit is seven companies, against five for WIG20, and the buffer is wider: ranks 1 to 20 are in and 41 or lower are out at the annual revision (1 to 15 and 46 or lower at quarterly adjustments). ## References - [GPW Benchmark: GPW Benchmark, GPW Benchmark Indices, March 2026 edition (index profiles, calculation principles and periodic modifications)](https://www.gpwbenchmark.pl/pub/BENCHMARK/files/PDF/opis_indeksow/IndicesGPWB_0326.pdf), as published 2026. Every rule described on this page is taken from this document. ## Current WIG30 constituents GPW Benchmark publishes and licenses the WIG30 constituent list. Swoopr does not republish it here. The provider's own page is the authoritative source for current membership and weights. [GPW Benchmark: official WIG30 page](https://gpwbenchmark.pl/en-home) ## Related reading - [All stock market indexes](https://www.getswoopr.com/stocks/indexes/): how indexes are built, weighted and revised. - [Europe indexes](https://www.getswoopr.com/stocks/indexes/europe/): others covering the same region. - [Index concentration](https://www.getswoopr.com/technical-analysis/market-concentration/index-concentration/): measuring how much of an index sits in its largest holdings. - [Index rebalancing and inclusion effects](https://www.getswoopr.com/stocks/corporate-actions-catalysts/index-rebalancing-and-inclusion-effects/): what happens to a stock when index membership changes. ## Frequently Asked Questions ### Who maintains the WIG30? GPW Benchmark maintains the WIG30 and publishes the methodology document that defines its eligibility and weighting rules. ### What does the WIG30 measure? It measures Polish 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 WIG30 constituents? GPW Benchmark publishes the current constituent list. Swoopr does not republish it, because index providers license constituent data and Swoopr holds no such licence. ## About the author The [Swoopr Editorial Team](https://www.getswoopr.com/authors/swoopr-editorial-team/) writes Swoopr Investment's educational library, covering market structure, analysis methods and the mechanics behind the numbers investors read every day. Our [editorial policy](https://www.getswoopr.com/legal/editorial-policy/) and [corrections policy](https://www.getswoopr.com/legal/corrections-policy/) set out how this content is produced, reviewed and fixed when it is wrong.