The Switzerland 20, or the Swiss Market Index (SMI), is Switzerland's most valuable blue-chip market index. The SMI index consists of the 20 largest and most traded mid- and large-cap stocks, according to the Swiss Performance Index. Founded in 1988, the index had a baseline value of 1500 points. The SMI index composition is re-examined annually. The index is calculated in real-time. The updated index level is displayed as soon as a new transaction with a security included into the index takes place. The securities of the Swiss Market Index account for 90% of the entire market capitalisation and 90 of the trading volume of Switzerland's and Liechtenstein's equities traded on the SIX Swiss Exchange. Considered a benchmark of the Swiss stock market, the SMI is the underlying index for various derivative instruments.