Below is my trading plan in regard to option spread. If you follow it and make small fortune, buy me a beer someday...

All comment welcome ! (I attach my excel spreadsheet if anybody interested)
1. Determine the maximum loss and maximum profit.
2. Set your target on the range from (1) above
3. Monitor price movement and stick to the trading plan
4. Grab "bonus" profit
1. Determine the maximum loss and maximum profit.
For spread strategy, we know that the maximum profit is to let both legs of the options (written one and bought one) expired worthless.
Net Profit = Max Profit - Entry Cost
where entry cost is the brokerage + clearing house fee for 2 legs
The maximum loss is:
Net Max Loss = The Spread + Entry Cost + Exit Cost - Max Profit
where exit cost is another 2 legs (selling your bought option and close out your written option)
For example,
- if the ROI is around 25% (which is quite average) - $1 spread give you 25c profit</li>
- if you have 10 contract (each contract is 1000 share in Australia, not 100), the profit is $2500. The brokerage is around $100 (for both leg) or about 5% which is acceptable
- Net Max Profit is $2,400
- Net Max Loss is $10000 + $100 + $100 - $2500 = $7,700.
So in this example your possible outcome of this trade is within -$7700 to +$2400
But if you have smaller contract, do another calculation like above with smaller contract and you find that the brokerage cost is eating your profit significantly
2. Set your target on the range
Say you want at least $1900 in profit ($500 or around 20% off from max profit) and max loss is $1400 (always make your profit higher than stop loss - you will be profitable in long run)
3. Monitor price movement and stick to the trading plan
- if the price move in favor of your position (move up for bull put spread -or- move down for bear call spread), check how much needed to buy back your written option. If it's below $500 (see above), close it.
- if the price moves against your position, always check the difference between both leg as if you close them all. If it is above $1400, close them out and you're out-done.
4. "bonus" profit
once you have closed the written option (you achieve your minimum profit) - do not sell the bought option yet. let it run until finish see if you can grab additional profit should the market bounce back against your initial position.