This ended the bull market that had reached an all-time record closing price short of 13,000[8] on 28 December 2021.

As soon as a new transaction occurs in a security contained in the SMI, an updated index level is calculated and displayed.

Because the SMI is considered to be a mirror of the overall Swiss stock market, it is used as the benchmark for numerous mutual funds, index funds and ETFs, and as the underlying index for numerous derivative financial instruments such as options, futures and structured products.

To be accepted into the SMI, a given issue must meet stringent requirements with regard to liquidity and market capitalization.

[citation needed] The SMI comprises a fixed number of 20 securities as of the ordinary review date in September 2007.

[citation needed] It is worth noting that the number of constituents of the index (20) is below the generally accepted minimum sample size of 30 required to reach statistical significance.

[citation needed] In 2017, in order to address the issue that the top three constituents (Nestlé, Roche, Novartis) account for more than 60% of the index capitalization, SIX Swiss Exchange changed the rules of the SMI to introduce capped weighting.

[citation needed] Readjusting any weight exceeding 18% down to that value is done, in principle, on a quarterly basis.

The latest update following the ordinary review was implemented in June 2023, when Kuehne + Nagel replaced Credit Suisse Group.