### Comment:
isnt there parity between the debit and credit spreads? if not we could make a lot of money with arbitrage

### REPLY:
There certainly should be. I think technically the parity is skewed by interest rates. But short-term, in this environment, that's irrelevant. 
  
 I don't think I've ever sold an in-the-money credit spread. Surely we could, identical to an out-of-the-money debit except with less capital outlay. But I just don't think that way. Credit spread for decay, debit spread for movement.

### END.