... 1 point decrease in the underlying, the combined delta decreases by 0.026: the put increases its delta by 0.013, and the call decreases its delta by 0.013. In other words, as the underlying ... want to know how the crash of 1 987 and the grinding retracement of 1 988 affected OEX implieds, how in turn the implieds mul-tiplied the vegas, and how in turn the vegas affected the options prices, ... the December 380 call will then be 14.For out-of- and in -the- money options, the vega itself increases as the implied increases, and it decreases as the implied decreases. Therefore with these...