I calculated again after you pointed out your doubt. What I meant to convey was that I was to able keep 50 % of profits of all 4 trades.
Following is the table of calculation of all trades for JAN'10 and the aftermath.
If you will note I had to square 3 put options but still in these three trades I was able to keep some money. I paid quite high premium for NIFTY PUT at Rs. 27 which I had sold for 18.50. For DLF PUT I paid slightly high premium of Rs.8.125 for the premium I had collceted was Rs.7.175. And for TATA MOTORS PUT I paid lower premium of Rs 4.2176 for the premium I had collected was Rs. 5.8.
of course, the spurt in volatility was at the end of the series so options did not contain much of time value, that was fortunate part for me.
Now I am trying an add-on approach ,at least, for NIFTY options.
While calculating for Implied volatility, I found that present Implied volatility for call and put options is in the ration of 2:3.
i.e. if IV of 5200 CALL was 19% then IV for 4500 PUT was around 28%. As the downside risk is more and it is very easy to slide down on any weak sentiment and perhaps presently the market sense weak sentiment also.
Therefore, I have decided to sell put:call option in the ratio of 2:3. Two put options and three call options to make a strangle.
For Feb'10 series I have sold 2 NIFTY 4500 PUT options for Rs.32-00 and 3 5200 CALL options , that also distribute the buffer as well.
I get higher buffer for lower side and lower buffer for higher side. i.e. I have total cushion of Rs. 89-00 for 2 PUT options as against Rs.70-00 , I would have in 1:1 ratio. At the same time cushion for CALL options decrease to Rs.59-00 which could be Rs. 70-00 if the ratio was 1:1.
I have also sold TATA MOTORS 500 PUT for 8.00 when the stock was hovering around the support level of Rs. 560-00, today the stock has bounced back to from the level to 579-00