No. The Greek (Theta) represents how much money you get after the end of the trading day. Theta only suppose to be negative when buying options because of time decay that's it. You want Theta positive at all cost when selling options. When you sell a contract or whatever it should show you that Theta is positive but once your strategy or whatever you use turns something like this -900.81. Your in trouble. This means that after each end of the trading day your losing $900 and 81cents. Any more questions I would be glad to answer.
I knew that. Somehow I am more biased into selling naked options. If I know a stock will go up a little, I sell PUT and if I know that a stock will pull back, I sell call and in range bound stocks, I sell both PUT and call. rarely I do risk reversal. I have a receiving hand and rarely I give. I was surprised by the comment that "when you sell an option, you have to make sure that your theta is positive. It WILL be always positive.
Vega is a killer in out of the money options. I have sold options for 5 cents on Thursday before option expiry day and on Friday, the option was worth $1.4 !!!. I don't do it anymore on stocks. If I want to do it, I do it on ETFs. But it is playing with fire specially for small accounts.
Not necessary mostly 95% of options is overpriced because of Volatility. So it's no need to look at Vega unless you want too. But that's a good question because the higher the Vega is the more money you make from option premium once it expired so I kinda look at Vega but also remember you can still profit from low volatility and high volatility. Always remember. The only reason why people look at Vega to see if they can profit from the option contract being overpriced.
Nastynate - I agree put options are in general overvalued since the '87 crash (esp after the housing bust) b/c of a persistent bid for downside protection. However, that doesn't mean they can't become more overpriced during a black swan. For example, you sell an "overvalued" put for 2.5 b/c you think the fair value is 2.25 but a black swan event causes the price to explode to 25.