中文：

上证指数，全称为上海证券交易所综合指数，是上海证券交易所编制的一种股票指数，反映了上海证券市场整体价格变动情况。它涵盖了上海证券市场所有上市股票，以流通股本加权计算，以1990年12月19日为基准日，基点为100点。

上证指数的编制遵循公开透明的原则，以样本股的代表性、流通性为基础，选取样本空间内所有样本股，采用加权平均法计算。样本股包括在上海证券交易所上市的全部上市股票，但不包括ST股票和PT股票。

上证指数的波动反映了市场整体走势，可以为投资者提供重要的参考信息。同时，上证指数也是中国股票市场的重要指标之一，被广泛应用于市场分析、投资决策等领域。

英文：

The Shanghai Stock Exchange Composite Index, also known as the SSE Composite Index, is a stock index compiled by the Shanghai Stock Exchange that reflects the overall price movement of the Shanghai stock market. It covers all listed stocks on the Shanghai Stock Exchange, weighted by circulating capital, with December 19, 1990 as the base date and a base point of 100 points.

The compilation of the SSE Composite Index follows the principles of openness and transparency, based on the representativeness and liquidity of sample stocks, selecting all sample stocks in the sample space and calculating using weighted average method. Sample stocks include all listed stocks on the Shanghai Stock Exchange, excluding ST and PT stocks.

The fluctuations of the SSE Composite Index reflect the overall trend of the market, providing important reference information for investors. The index is also an important indicator of China's stock market, widely used in market analysis, investment decision-making and other fields.