An index is a collection of a group of assets such as stocks and bonds that's used to track the performance of a specific sector or the broader market. A financial index produces a numeric score ...

A stock index is a collection of stocks intended to be reflective of the stock market as a whole or, in some cases, a particular industry or segment of the market. In other words, a stock index ...

Index funds are mutual funds that seek only to mirror the performance of an underlying stock market index — not to outperform ...

The refractive index of a vacuum is 1.0 ... 3.5 Germanium 4.0 ** = air is a tiny franction greater than 1.0 THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.