rdemyan:
Yes, I'm thinking of the actual iv for each strike calculated. Of course, you'd have to make some estimate, but it seems possible if done in excel. For example, the short put has a lower iv and the long put a higher iv relative to each other when the spread is initially placed. If an adjustment is necessary (assume a debit adjustment with the underlying falling in price), the relative difference in iv between the 2 options might change making the predicted spread price not so obvious. It seems like the price of the spread could be influenced by 2 factors: the iv curve or skew will be shifted upward (underlying has fallen), so that iv at all strikes is higher, but also now you will BTC the short put (the position with the relatively lower vol) and STC the long put (the position with the relatively higher vol).
Yes, I'm thinking of the actual iv for each strike calculated. Of course, you'd have to make some estimate, but it seems possible if done in excel. For example, the short put has a lower iv and the long put a higher iv relative to each other when the spread is initially placed. If an adjustment is necessary (assume a debit adjustment with the underlying falling in price), the relative difference in iv between the 2 options might change making the predicted spread price not so obvious. It seems like the price of the spread could be influenced by 2 factors: the iv curve or skew will be shifted upward (underlying has fallen), so that iv at all strikes is higher, but also now you will BTC the short put (the position with the relatively lower vol) and STC the long put (the position with the relatively higher vol).
Quote from rdemyan:
The only skew I know about is the skew in volatility for puts relative to calls. Are you talking about using the actual implied volatility for each different option? The curves did use a constant volatility for each option that was just assumed at 15% for the first graph and 20% for the second.