中文：

分类指数是证券市场中的一种指数，它是通过对股票、债券等证券品种进行分类，选取代表性证券品种编制而成的。分类指数的编制方法通常采用加权平均法或算术平均法，其目的是反映特定证券品种的整体表现。

分类指数通常按照证券品种的特点和属性进行分类，例如大盘股指数、中小板指数、创业板指数等。这些指数在市场分析和投资决策中具有重要的作用。通过观察分类指数的变化，投资者可以了解特定证券品种的整体表现和市场趋势，从而更好地把握投资机会和风险控制。

分类指数还可以用于评估投资组合的表现。例如，投资者可以通过比较投资组合与分类指数的涨跌情况，评估投资组合的收益和风险水平是否符合预期。此外，分类指数还可以用于衡量市场的风险和收益水平，为投资者提供参考。

英文：

Classification index is a type of index in the securities market, which is compiled by selecting representative securities品种 after classifying stocks, bonds and other securities. The compilation method of classification index usually adopts weighted average method or arithmetic average method, aiming to reflect the overall performance of specific securities品种.

Classification index is usually classified according to the characteristics and attributes of securities, such as large cap stock index, small and medium board index,创业板指数, etc. These indices play an important role in market analysis and investment decision-making. By observing the changes of classification index, investors can understand the overall performance and market trends of specific securities, so as to better grasp investment opportunities and risk control.

Classification index can also be used to evaluate the performance of investment portfolios. For example, investors can compare the rise and fall of investment portfolios with classification indexes to evaluate whether the return and risk level of investment portfolios meet expectations. In addition, classification indexes can also be used to measure the risk and return level of the market, providing reference for investors.