市盈率 Price–earnings ratio
（重定向自Price to earnings ratio）
股票的市盈率（Price-to-Earning Ratio，P/E或PER），又称为本益比，指每股市价除以每股盈利（Earnings Per Share，EPS），通常作为股票是便宜抑或昂贵的指标（通货膨胀会使每股收益虚增，从而扭曲市盈率的比较价值）。市盈率把企业的股价与其制造财富的能力联系起来。
每股盈利的计算方法，一般是以该企业在过去一年的净利润除以总发行已售出股数。市盈率越低，代表投资者能够以相对较低价格购入股票。假设某股票的市价为24元，而过去一年的每股盈利为3元，则市盈率为24/3=8。该股票被视为有8倍的市盈率，即在假设该企业以后每年净利润和去年相同的基础上，如果不考虑通货膨胀因素，回本期为8年，折合平均年回报率为12.5%，投资者每付出8元可分享1元的企业盈利。但上市公司通常只会把部分盈利用来派发股息，其余用来作进一步发展，所以市盈率的倒数不等于股息率。
![Robert Shiller's plot of the S&P composite real price–earnings ratio and interest rates (1871–2012), from Irrational Exuberance, 2d ed.[1] In the preface to this edition, Shiller warns that](/uploads/202502/04/S_and_P_500_pe_ratio_to_mid20120429.png)
![Price-Earnings ratios as a predictor of twenty-year returns based upon the plot by Robert Shiller (Figure 10.1,[1] source). The horizontal axis shows the real price-earnings ratio of the S&P Composite Stock Price Index as computed in Irrational Exuberance (inflation adjusted price divided by the prior ten-year mean of inflation-adjusted earnings). The vertical axis shows the geometric average real annual return on investing in the S&P Composite Stock Price Index, reinvesting dividends, and selling twenty years later. Data from different twenty-year periods is color-coded as shown in the key. See also ten-year returns. Shiller stated in 2005 that this plot](/uploads/202502/04/Price-Earnings_Ratios_as_a_Predictor_of_Twenty-Year_Returns_(Shiller_Data)0429.png)
