Stocks have to be traded in more than 75% of the total number of trade days in the selected time period in order to be included into CROBEX. The stock ranking is determined by weighing the stock's
free float market capitalization as a proportion of the total, and its traffic as a proportion of the total share traffic in the six-month time period observed. The index is revised every third Friday of March and September. The Index Commission can revise the index if the following extraordinary events happen: • bankruptcy or liquidation of a company, increase or decrease in the base capital of a company, takeover, merger. • removal of a stock listing • long-term suspension of trade of a stock There are also other circumstances related to the issuer or the stock that can affect the quality of the CROBEX index that can cause the commission to revise the index. A special revision can happen to include a new stock in the index in case the stock, in the first 30 days since its listing date, is traded in 100% of the total number of trade days, taking into account its free float market capitalization and share of traffic. ==Composition==