The SMI Expanded comprises the SMI and the SMIM and hence the 50 most highly capitalised securities in the Swiss equity market. It represents about 95% of the capitalisation of the freely tradable shares of the Swiss equity market and is calculated both as a performance index and as a price index.
The SMI Expanded was standardised at 1'000 points on 31 December 1999 for the performance index and at 100 points for the price index. It was introduced on 15 November 2004. In order to facilitate trading and comparability, on 2 August 2005 the price index was retroactively standardised at 1'000 points as of 31 December 1999.