The MSCI World is one of the most renowned equity indices worldwide. The name stands for Morgan Stanley Capital International World Index. This share index comprises over 1500 large and mid-cap shares from 23 selected industrialized countries, which is why it is regarded as a barometer for global developments on the stock markets. It is calculated by Morgan Stanley Capital International (MSCI), which focuses on broad geographical and sectoral diversification with companies from Asia, Europe, Australia and North America as well as various industries. Companies from emerging markets cannot be included in the MSCI World; they are included in the MSCI Emerging Markets Index.

The composition changes quarterly and is subject to numerous influences and criteria. For example, the index aims to cover over 80% of the free-float market capitalization in each country included. It also aims for broad diversification, which includes mid-cap companies. Other factors include the liquidity of the companies, their free-float adjustment and much more.

The MSCI World serves as a barometer of the performance of the global stock market. It is used as a benchmark index to check how other investors are performing in comparison. To the extent that higher returns are achieved than those of the MSCI World, the investor has "outperformed the market".