The WIG is a total-return index of eligible Warsaw Main Market shares. Learn its free-float weighting, diversification limits, and uses.
The WIG Index is a broad total-return equity index covering companies on the Warsaw Stock Exchange Main Market that meet GPW Benchmark’s eligibility rules. It reflects both share-price changes and income from dividends and subscription rights. WIG is broader than WIG20, mWIG40, or sWIG80, but it is not an unfiltered list of every security traded in Warsaw.
WIG measures the return of a broad portfolio of eligible shares listed on the Warsaw Stock Exchange’s regulated Main Market. GPW Benchmark’s public methodology applies minimum participation criteria rather than automatically including every listed company. The provider’s published criteria address free float, investable value, recent trading, liquidity classifications, and special issuer status.
This makes WIG an all-share-style benchmark, not literally an all-securities index. Bonds, exchange-traded products, and companies that fail the equity-index criteria are outside its portfolio.
WIG is also broader than a Poland-only domicile index. The exchange separately maintains WIG-Poland for domestic companies, so analysts should not infer legal domicile or revenue geography from WIG membership alone.
For a simplified constituent, free-float market value is:
where (P_i) is the share price, (Q_i) is the relevant share count, and (F_i) represents the portion treated as freely tradable. A simplified weight before caps is:
GPW Benchmark’s index card says constituent packages are based on free-float shares and rounded to full thousands of shares. At the scheduled ranking, a single company’s weight cannot exceed 10%, and companies from one exchange sector cannot collectively exceed 30%. Packages above those limits are reduced.
These are review-date controls, not a promise that published weights can never move above the thresholds between rankings. Market prices change every day.
Assume a simplified uncapped three-company portfolio:
| Company | Full market value | Free-float portion | Free-float market value | Uncapped weight |
|---|---|---|---|---|
| A | PLN 40 billion | 25% | PLN 10 billion | 25% |
| B | PLN 30 billion | 80% | PLN 24 billion | 60% |
| C | PLN 15 billion | 40% | PLN 6 billion | 15% |
| Total | PLN 85 billion | PLN 40 billion | 100% |
Company A is largest by full market value, but Company B has the largest uncapped weight because more of its shares are in free float. In the actual WIG review, the company and sector caps would require further package adjustments; the final weights would therefore differ from this uncapped illustration.
A price index measures changes in constituent prices. A total-return index also reflects distributions according to its methodology. Conceptually:
The exact relationship is path-dependent because payment dates, reinvestment, corporate actions, weights, and constituent changes matter. GPW Benchmark states that WIG includes income from dividends and subscription rights as well as share-price changes.
For example, suppose a simplified WIG portfolio starts at 100, falls to 98 on price movement, and receives distributions worth 3 index points that are incorporated under the methodology. Its illustrated total-return value would be approximately 101, not 98. This is a teaching example, not the official calculation for any date.
WIG began with a base level of 1,000 on April 16, 1991. A simplified index-level representation is:
where (Q^{index}_{i,t}) is the share package used in the index and (D_t) is a continuity divisor or equivalent adjustment term. Total-return adjustments preserve the value of eligible distributions, while corporate-action and portfolio adjustments prevent mechanical changes from being mistaken for investment performance.
An index level such as 100,000 is not a PLN amount invested and cannot be compared meaningfully with another index’s point level. Use percentage returns over matching dates.
The current GPW Benchmark index card describes the maintenance cycle as follows:
Methodology, calendars, and eligibility details can change. Membership claims should be checked against the latest GPW Benchmark portfolio and review notice rather than copied from an old constituent list.
| Index | Main scope | Constituent count | Return convention |
|---|---|---|---|
| WIG | Broad eligible Warsaw Main Market | Variable | Total return |
| WIG20 | Largest and most liquid segment under its rules | 20 | Price index; separate WIG20TR exists |
| mWIG40 | Medium-sized segment under its rules | 40 | Price index; separate total-return version exists |
| sWIG80 | Smaller-company segment under its rules | 80 | Price index; separate total-return version exists |
The segment indexes are not simple partitions chosen only by current market value. Their own liquidity, ranking, eligibility, and review rules apply. A return comparison should use consistent price or total-return versions.
WIG is not a direct measure of Poland’s gross domestic product. Publicly traded companies are only part of the economy, index weights follow market values rather than economic output, and listed companies can have significant foreign operations.
This article is educational and does not provide investment, tax, or legal advice or recommend an index product, security, derivative, or allocation.