Some examples of major stock market sectors include energy, financials and information technology, according to Bloomberg. As of 2015, the energy sector includes three industries while both the financials sector and information technology sector includes over 10 industries each.
Within the energy sector, Bloomberg lists over 200 companies, such as First State Bank and First Solar, Inc.. The energy sector includes the energy industry, the energy equipment and services industry and the oil, gas and consumable fuels industry. As of 2015, the financials sector has well over 500 companies that fall into different industries such as real estate, insurance and banks. The software industry and communications equipment industries are part of the information technology sector.