, commonly known as TOPIX, along with the Nikkei 225, is an important stock market index for the Tokyo Stock Exchange (TSE) in Japan, tracking all domestic companies of the exchange's Prime market division. It is calculated and published by the TSE. , there were 1,669 companies listed on the First Section of the TSE, and the market value for the index was ¥197.4 trillion. The index transitioned from a system where a company's weighting is based on the total number of shares outstanding to a weighting based on the number of shares available for trading (called the free float). This transition took place in three phases starting in October 2005 and was completed in June 2006. Although the change is a technicality, it had a significant effect on the weighting of many companies in the index, because many companies in Japan hold a significant number of shares of their business partners as a part of intricate business alliances, and such shares are no longer included in calculating the weight of companies in the index. The TOPIX index is traded as a future on the Osaka Exchange under the ticker symbol JTPX. The CQG contract specifications for the TOPIX Index are listed below. TSE currently calculates and distributes TOPIX every second and further plans to launch a new High-Speed Index dissemination service provided at the millisecond level starting from February 28, 2011. History of TOPIX 1969-07-01 TSE to begin calculating and publishing “TOPIX” and “TOPIX Sector Indices” 1969-08-18 TSE to begin calculating and publishing “Tokyo Stock Exchange Second Section Stock Price Index” 1988-09-03 TOPIX Future Trades begin at TSE 1989-10-20 TOPIX Option Trades begin at TSE 1998-08-02 TSE to begin calculating and publishing “TOPIX New Index Series” 1999-02-01 TSE to begin calculating and publishing “TOPIX Total Return Index” 2001-07-13 TOPIX ETF Trades begin TSE 2003-08-01 TSE to begin calculating and publishing “Tokyo Stock Exchange REIT Index” 2003-09-16 TSE to begin calculating and publishing “Tokyo Stock Exchange Mothers Index” 2005-10-31 Introduction of Free Float Adjusted Indices (Shift in three phases) 2005-11-17 Lyxor AM (Lyxor Asset Management) introduces Lyxor ETF Japan (TOPIX) for trading on Euronext Paris 2006-04-05 Lyxor (Societe Generale) lists on Borsa Italiana the world's most cost-effective and diversified Japan-based UCITS III compliant ETF with TOPIX as the underlying index 2006-04-25 Development of New Custom Index that incorporates Corporate Social Responsibility (CSR) 2006-06-30 Free Float adjustment for TOPIX completed 2006-08-09