The Swiss Market Index (SMI) is the primary stock market index in Switzerland, representing the 20 largest and most liquid companies listed on the SIX Swiss Exchange. It serves as a key indicator of the overall performance of the Swiss equity market and includes well-known firms such as Nestlé, Novartis, and Roche. The SMI is calculated using a free-float market capitalization method, which means it considers only the shares available for trading. This index is widely used by investors and analysts to gauge market trends and make informed investment decisions in the Swiss financial landscape.