, not necessarily a fixed method. but in addition to the gann levels i take for support and resistance, i also rely on visual input to analyse the market, i keep looking at the market movement to get a feel of it's strength , many may not agree with me but it is a good indicator . i can usually get a sense of the market direction looking at how easily or how tediously the market moves in either direction. so, based on all these i decide on the closing of a position. so when i saw the market struggling to move upwards after racing in the morning i realised it may stall or fall. so i not only closed my position i decided to take a reverse position if it keeps struggling.
i expect some sort of premium eating may happen. and this will be rapid in ATM and ITM options more than OTM. so i picked a little far off one to carry for next week too. ( current feeling). but if it moves against me drastically today or in my favour i may cover it. , because in spite of my best efforts the market refuses to listen to what i want