Endeksler, or indices, are statistical measures that represent the performance of a specific group of assets, such as stocks or bonds. They are commonly used in finance to track market trends and assess the overall health of an economy. For example, the Borsa İstanbul index reflects the performance of publicly traded companies in Turkey. These indices are calculated using various methods, often based on the prices of the underlying assets. Investors and analysts use endeksler to make informed decisions about buying or selling investments. Popular examples include the S&P 500 and the Dow Jones Industrial Average, which track the performance of major U.S. companies.