Quote from rallymode:
Well i am no mo but perhaps it would help if you think of the position as a short straddle. The synthetic compotent allows for better fills and more control over your offset/adjustment.
Previous posts referred to theta decay while being short gamma in a vertical. The suggested position is a pure short gamma play within 1 sigma or two in whatever time interval you follow. The position benefits from theta much much better than a vertical. If market moves towards your short OTM strikes, you will have some delta gains as you have a short bias and vega gains as you originally sold skewed strikes. Throw in some theta decay and you get what risk referred to as an edge to offset or buy the wings. You would want to do that as your deltas are going to invert, shorts puts will carry higher total deltas against your futures. Position requires watching it/trading it actively as you will want to offset leg(s)s on the rallies/pullbacks to stay close to neutrality within your bias.
I am sure mo will add more to it.
I would add that it's gains to dvega position [fat vegas] over vega gains in terms of smile-sensitivity. The majority of gains are from delta as one would expect.
Be sure to compare the synth straddle premium to the atm straddle. It should give you an idea of the gains that may be seen with a move to neutrality on the "delta straddle" you've sold, synthetically.