Indices, also known as indexes, are portfolios of stocks. These stocks are grouped together depending on their unique characteristics. For example, the German stock market index, known as the DAX 30, consists of 30 biggest German companies trading on the Frankfurt Stock Exchange.
What are mini indices?
Buying and selling the mini version index gives you the same exposure to that index, but for a cheaper price. It's easy to spot a mini. Look out for the 'm' at the end of the name of the index you're looking to trade. The ND100m includes stocks from the top technology companies in the US, just like the ND100, but with a smaller contract size.