All stock indices to date: 15/11/2024
A stock index is a general index calculated on the basis of the prices of a certain group of securities in the “index basket”.
When calculating an index, its initial (base) value can be the sum of prices or be equated to an arbitrary number (for example, 100 or 1000).
For comparability, prices are often multiplied by additional coefficients, so the absolute values of the indices are not important, but the changes in the index over time are important, which allows us to judge the general direction of price movement in the index basket, despite the fact that stock prices are inside the "index basket" can change in different directions. Depending on the principle underlying the choice of securities for the index, it can reflect the price dynamics of a group of securities united by some criterion (for example, high, medium, small stock capitalization) of the selected market sector (for example, telecommunications), or the broad stock market as a whole.
A stock index is not a single security, so one usually speaks of the “value” or “level” of the index, but not the “price”. But at the same time, stock indices are often the basis of derivatives of the same name (index futures or options), which are used for investment and speculative purposes or for hedging risks. In this case, the value of the index is interpreted as the price of this instrument.