mgt490industries

The North American Industry Classification System (NAICS) is maintained by the U.S. Census Bureau. It's a replacement for the Standard Industrial Classification (SIC) system which was used for years. The most current classification list is 2007 NAICS. From the hierarchical list, note the progression for general 2 digit to detailed 6 digit industry. Even at looking at the list of 6 digit codes organized by 2 digit sector (the six digit codes are still often referred to as 'SIC codes', this is a serious list with lots of detail. The detail comes in handy for research and government work, but many view this industry classification as too cumbersome and bureacratic.

Standard & Poor's Global Industry Classification System (GICS)

Many like to use the Global Industry Classification System (GICS) developed by Standard & Poors for their various stock indices like the S&P 500 Index. There are 10 industry sectors in this scheme: consumer discretionary, consumer staples, energy, financials, healthcare, industrials, info tech, materials, telecom services, and utilities. At the top of page 2, note the hierarchy (and numbers of each as of 4/28/06) :

Sectors (10 of them) >> Industry Groups (24) >> Industries (64) >> Sub-Industries (147)

This fact sheet shows the market values of industries represented by the 500 companies in the S&P 500 index.

While intuitive and well organized, GICS is proprietary, meaning that others can't adopt this framework without paying a fee. So if you go to Yahoo Finance, Google Finance, or elsewhere for industry info, you'll see slightly different industry sector categories.

Google Finance

Google Finance offers 12 industry sector categories (see below). I'm not sure of the basis for this scheme but I like it. Note that on each of the industry sector landing pages below, you'll find industry sub-sector categories as well. Very nice.

Consumer Non-Cyclical