The Nigerian Stock Exchange (NSE), formerly known as the Lagos Stock Exchange, is the sole stock exchange of Nigeria. It is headquartered in Lagos, the country's largest city and a major financial centre in Africa. It is a member of the Sustainable Stock Exchanges, a project of the United Nations, and is regulated by the Securities and Exchange Commission of Nigeria. NSE is the third largest stock exchange in Africa with 176 listed companies and a total market cap of $28 billion. Foreign investors of any nationality are free to invest. The exchange also houses ETFs, bonds and various derivatives. Among the listings are well-known and actively traded companies such as Zenith Bank, Dangote Cement, FirstBank, Conoil and Nigerian Breweries. NSE manages many indices. One of them is the All Share Index, a broad index tracking the market movement of all listed companies. Other key indices are the Premium Index, tracking the performance of big companies that adhere to stringent governance criteria, and the NSE Top 30, tracking the top 30 companies in terms of market capitalization and liquidity. NSE also manages indices that reflect the performance of different sectors and industries such as Banking, Oil and Gas, etc.