A stock price index is an essential tool for investors to gauge the performance of the stock market. However, there are various words used interchangeably as synonyms for a stock price index. For instance, stock market index, market barometer, benchmark index, and stock index are frequently used terms that are equivalent to a stock price index. These terms quantify the price movements of a set of the most significant securities traded on the exchange, giving investors insight into the overall health of the stock market. While there are subtle differences among them, the use of synonyms for stock price indices is helpful in conveying a broader understanding of financial markets.