TL;DR? "There are no differences between credit and debit spreads." If there were then boxes would be traded until flat/edge was gone. Nobody is handing you a box-edge at mkt.
The probability of making money on a credit spread is greater than that of a debit spread. I just made .31 cents on a credit spread at expiry that would have been worth .04 cents as a debit spread.
Merry Xmas everybody! Below is a short call, and a long put. Both are to capitalize on a downtrend. If the price doesn't move by expiry then the short call P/L is $62.30 whereas the long put is $-94. The price would have to move up to 203.06 by expiry for the short call to suffer the same losses that the long put. P.S . D, I appreciate your explaining as I know you do not suffer fools and I will read through your posts thoroughly to decipher what it is that I'm not comprehending.
@wxytrader it’s very straightforward, you just need to abstract yourself from “probability” for a moment. 1. a call spread and put spread with the same strikes is the same thing in terms of the payoff - you make money linearly from k_low to k_high and are flat outside of this range. You can draw that on a napkin and prove to yourself that it’s true. 2. the premium for call spread and put spread are going to add to the difference between strikes, with a spread that has higher moneyness having bigger upfront premium. Again, you can prove it to yourself by taking two calls and using put-call parity to convert each price to a put with the same strike. 3. the only “miracle” here is that your upfront premium is discounted by the interest rate which is why if you combine two spreads in a box, you’re guaranteed to make roughly the prevailing funding rate. If you take a market price of that structure (it’s called ze box), you can take the difference between strikes, divide by the premium and, after multiplying by appropriate year fraction (eg 1 month box you’d multiply by 12) you will back out interest rate.
Ok I think this is what you are talking about... https://corporatefinanceinstitute.com/resources/derivatives/put-call-parity/ https://analystnotes.com/cfa-study-notes-explain-put-call-forward-parity-for-european-options.html#:~:text=Consider the following example:,the price of the put. https://www.investopedia.com/terms/p/putcallparity.asp Can you show an example? The second link had a downloadable spreadsheet that calculates put/call value to determine if there is parity. I entered in the data for IWM Jan19 201 call. It shows parity with a put price of 4.38 but current puts are only 4.17.
My tool gives for DTE=30 (t=0.08) a Put price of 4.21. DTE=32 gives about 4.17. It depends also on which Call price you took: Bid, Ask, or MidPrice? Should be MP.