Hey! I have tried my hardest to read as much as I can about this before posting but im stuck. please help
Lets Say the FTSE100 is trading at 7110. To buy a call at 7110 is 20, and the spread is 5. To buy a put at 7110 is also 20, and spread is also 5 (I am trying to straddle)
Now as soon as I buy both of these I am -£5 -£5 = -£10 profit/Loss
I expect that if the market moves up 15 Points, My Short is now -£20 (the maximum I can lose), and my Long is now £-5 + £15 = £10.
If the market moves back down 15 Points I expect to be back to -£10 profit/Loss again
This does not seem to be the case.
What happens seems somewhat random, With me starting out at -£10 P/L and ending up at say -£20 P/L. How can this happen If I straddle both "at the money" and my strike price is the opening price of the trade, given that both options have the same price and spread?
I know that the various "greeks" determine the opening price for an option, do they also control how much the option moves during the trade? can they change during the trade?