When selling options, e.g. a straddle I read often the optimal time for selling options is 30-40 days until expiration.
For me intuitively the optimal time would be around one week until expiration because the option will loose most of it's time value in the last week (theta is highest).
So for example when we look at the AAPL options and want to sell a ATM straddle on 8/15/2015:
- Selling the Aug. 21 116 Straddle we would collect 1.56+1.57=3.13 premium.
- Selling the Sep. 11 116 Straddle we would collect 3.50+3.39=6.89 premium.
So basically I could collect about 1/2 of the premium in the last week, and then do another trade next week and collecting another 3 premium and so on, so why is it more optimal to sell a lower theta position? Also the longer to expiration position has 3 times more time to go in an unfavourable direction.