引伸波幅
implied volatility
證券價格的估計波幅。一般而言，引伸波幅在熊市時擴大，在牛市時收窄，因為一般相信熊市的風險高於牛市。
Estimated volatility of securities prices. Generally, implied volatility in the bear market to expand, narrowed in a bull market, bear market because it is believed that the risk is higher than the bull.