Floridaâs tract of coral reefs has the honor of being the third-largest barrier reef ecosystem in the world. However, it could soon be a thing of the past, as the acidification of the oceanâs water is dissolving it faster than it can rebuild.
index (plural indexes or indices) 1  An alphabetical listing of items and their location. The index of a book lists words or expressions and the pages of the book upon which they are to be found. 2  The index finger; the forefinger. 3  A movable finger on a gauge, scale, etc.
To understand what an index fund is, first we need to know what a stock market index is. A stock market index is a number that refers to the relative value of a group of stocks. As the value of the stocks in a particular index changes, the stock market indexâs number changes. If you watch or listen to the news regularly, youâve heard about stock indexes. Two of the most widely referenced stock market indexes are the S&P 500 and the Dow Jones.