A stock index is a basket of shares whose combined value is tracked through the day. The baskets differ widely across Asia’s exchanges.
The Nikkei 225 is weighted by share price, so an expensive share moves it more than a cheap one, as Nikkei’s index guidebook explains. Most others, such as the CSI 300 of Shanghai and Shenzhen shares, compiled by China Securities Index, and the Kospi 200 of the Korea Exchange, are weighted by the market value of the companies.
225companies in the Nikkei Stock Average, Japan’s best-known index, first calculated in 1950
When the paper reports an index, it says which one, and charts it against its own history rather than against another index measured differently.
