BSE-Sofia indices cover issues of securities, listed on any of the organised markets, which comply with the general and specific criteria of the respective index and accurately reflect the market performance. The indices include only issues of public companies, which have not been declared bankrupt or into liquidation, are not carrying out a company recovery plan or have not been temporarily suspended from trading. The minimum number of issues included in the indices is 5.

Currently BSE-Sofia calculates four indices - SOFIX, BGBX40, BG TR30 и BG REIT. The main index is SOFIX, which calculation started on October 20, 2000 with at innitial value of 100 points. SOFIX is based on the market capitalisation of 15 issues of common shares, adjusted with the free-float of each of them. SOFIX constituents must meet certain minimim criteria for liquidity, market capitalisation, free-float and number of shareholders.

BG TR30 index is based on the price performance of the common shares included in the index portfolio (30 issues), as each constituent issue has equal weight. BG REIT is a sector index, that covers 7 issues of common shares of real estate investment trusts (REITs) that operate in the field of securitisation of real estates and/or land, with the greatest market value of the free-float and the highest median value of the weekly turnover during the last 6 months.

BG BX40 is an index, that covers 40 issues of common shares with the greatest number of transactions and the highest median value of the daily turnover during the last 6 months. The calculation of BG BX40 started on January 01, 2014.