The SMI MID (SMIM) is a stock index which lists Switzerland's mid-cap companies. The index is calculated by SIX Swiss Exchange. It includes the 30 Prime Standard shares from sectors that rank immediately below the companies included in the Swiss Market Index. The company size is based on terms of order book volume and market capitalization. In 2020, the SMI MID, along with other SIX indices, was endorsed under the EU Benchmarks Regulation and is registered with the European Securities and Markets Authority, which means that it can be used as an underlying for financial products sold in the EU.