Stocks are categorized in various ways. One way is by the country where the company is domiciled. For example, Nestle and Novartis are domiciled in Switzerland, so they may be considered as part of the Swiss stock market, although their stock may also be traded on exchanges in other countries, for example, as American depository receipts (ADRs) on U.S. stock markets.
As of 2017, the size of the world stock market (total market capitalization) was about US$79.225 trillion. By country, the largest market was the United States (about 34%), followed by Japan (about 6%) and the United Kingdom (about 6%). These numbers increased in 2013.
As of 2015, there are a total of 60 stock exchanges in the world with a total market capitalization of $69 trillion. Of these, there are 16 exchanges with a market capitalization of $1 trillion or more, and they account for 87% of global market capitalization. Apart from the Australian Securities Exchange, these 16 exchanges are based in one of three continents: North America, Europe and Asia.