The Swiss Market Index SMI is a major stock market index which tracks the performance 20 largest and most liquid stocks based in the Swiss Exchange. It is a free-float, capitalization-weighted index. The SMI companies represent about 85 percent of the Swiss equity market. The SMI has a base value of 1500 as of June 30, 1988. Index performance for Swiss Market Index (SMI) including value, chart, profile & other market data. Index performance for Swiss Market Index (SMI) including value, chart, profile & other market data. Like the Dow Jones, the SMI is a price index. Consequently, the index level represents the average of the shares contained in it. Dividend payments are not considered in the index.