Nasdaq Composite
The Nasdaq Composite is a market-cap-weighted index of nearly all common stocks listed on the Nasdaq exchange, with a strong technology focus.
The Nasdaq Composite tracks thousands of stocks listed on the Nasdaq Stock Market, making it one of the broadest US indices by number of members. It includes US and non-US companies and covers common stocks along with some similar securities, such as real estate investment trusts and American depositary receipts.
It was launched in 1971 with a starting value of 100. The index is weighted by market capitalization, so the largest companies dominate its performance. Because Nasdaq is home to many big technology and internet companies, the Composite is often seen as a gauge of the technology sector, even though it includes companies from many other industries.
When the media say the Nasdaq rose or fell, they usually mean the Nasdaq Composite. It should not be confused with the Nasdaq-100, which includes only about 100 of the largest non-financial companies listed on the exchange.
The Composite is generally more volatile than the S&P 500 or the Dow, reflecting its heavier exposure to growth and technology stocks.
Example: a strong day for large technology stocks typically lifts the Nasdaq Composite more than the Dow.