Cyclically adjusted price-to-earnings ratio
The cyclically adjusted price-to-earnings ratio (CAPE, Shiller P/E, or P/E 10 ratio) is a stock valuation measure usually applied to the US S&P 500 equity market. It is defined as price divided by the average of ten years of earnings (moving average), adjusted for inflation.
Source: Wikipedia — Cyclically adjusted price-to-earnings ratio (CC BY-SA 4.0)