Amendment to the Rules for the Calculation of the PX, PX-TR and PX-TRnet Indices of the Prague Stock Exchange

The Index Committee of the Prague Stock Exchange has approved amendments to the Rules for the Calculation of the PX, PX-TR and PX-TRnet Indices of the Prague Stock Exchange. The amended Rules will enter into force on 1 December 2026 and will be applied to the index bases effective from 21 December 2026.

Key amendments

• Revision of the minimum market capitalization requirement for the inclusion of securities in the index base (Article 2.2.1)
• Limitation of the market capitalization of dual-listed securities based on the ratio of trading volume on the Prague Stock Exchange to trading volume on the issuer’s home exchange (Article 2.2.3)

Trading volume ratio	Number of securities included in the index calculation
Up to and including 4%	Number of securities admitted to trading on the Exchange × 5 × ratio, rounded up to the nearest multiple of 5
Above 4% up to and including 7%	Number of securities admitted to trading on the Exchange × 7 × ratio, rounded up to the nearest multiple of 5
Above 7% up to and including 10%	Number of securities admitted to trading on the Exchange × 8 × ratio, rounded up to the nearest multiple of 5
Above 10%	100% of the number of securities admitted to trading on the Exchange

• Introduction of a minimum 1% share of an issue’s market capitalization in the total market capitalization of the index base (Articles 4.1 and 4.2)

Detailed information

• The minimum market capitalization requirement will be increased from the current CZK 0.5 billion to CZK 0.75 billion.
• For dual-listed securities, the market capitalization included in the index calculation will be adjusted based on the ratio of trading volume executed on the Prague Stock Exchange to the trading volume executed on the issuer’s home exchange during the relevant six-month period. Depending on the calculated ratio, the number of securities included in the index calculation will be reduced according to the following table.
• A new requirement is introduced stipulating that the market capitalization of an individual issue must represent at least 1% of the total market capitalization of the index base.

Link to the new Rules

Source: Index Committee