Spent the majority of last week doing R/R analysis of various strategies involving vertical spreads. This analysis might cause me to adjust my allocation of funds as previously described.
The main question in my mind is one that has been addressed on this journal before; the idea that ATM credit spreads essentially have as riskarb puts it "the best r/r under one sigma". And as Momoney said, "The thing to bear in mind is that although your probability of success goes up the further OTM you are, your reward appears to go down at a FASTER rate than the gamma exposure goes up. So from that point of view, the best risk/reward really is ATM and it just gets worse from there."
I think this will always be a topic of debate. I have been trying to consider these questions not only pertaining to the statistical advantage of ATM, but also with regard to ease of execution and maintenace as this journal is more directed toward a slightly less experienced trader with a smaller bank roll. An ATM credit spread might have a better r/r but is also harder to adjust. ATM credit spreads might also require more diversification than OTM. Indeed the question is, what maintenance options does one have when an ATM credit spread is looking to expire ITM?
OTM/FOTM credit spreads can be adjusted when the underlying is approaching the short strike. The statistical probability of the underlying touching that point before expiration can be computed with a fair degree of accuracy. And it can then be stated that if that point is never touched, a worthless expiration will be the result. However, the risk management strategy for ATM spreads is much different. The probability of the short strike being ITM at some point before expiry is almost 100%. So an ATM position must be adjusted/exited after a certain amount of loss, and the probability of a certain amount of loss is difficult to calculate because it is so dependent on the time left to expiration.
So I'm looking for everyone's opinion on ATM credit spreads. If the underlying goes against you, are you inclined to exit the entire spread, reverse the position, or roll the position?