I try to break my risk capital down in segments that allow me to sell options every week or so. In simple terms, I take my risk capital (75% of total capital), divide it by 4 and sell options each week that consume 1/4 of my risk capital. This works well because the life-span of my positions is about 1 month. It never works out exactly this way because, for example, IWM was stubborn in January and did not allow options to get to my close point in 1 month’s time so I do have weeks where I do not trade. This gives you a basic idea of what I am doing. This approach does require four round-trip commissions per month instead of one. But, it averages the underlying instrument (IWM) moves so I never have all my capital tied up in a single trade that went horribly against me right away. I am willing to pay more in commission for this IWM price averaging.
For this blog I chose to track only one trade per month. I will probably keep it that way for a while, unless I get comments strongly in favor of seeing absolutely all trades.
I believe it is important to keep all risk capital in play but not to let all of my risk capital ride on one trade. Looking at actual results, the price movement in the IWM plays a considerable part in profitability when compared to volatility movement and time decay. So, by trading 1/4 of my risk capital each week, and with position life-spans being about 1 month, I can average the IWM price movements in segments of about 5 trading days. (trading once per week)
So, to recap, I have two rules about trading capital:
1) Keep a capital buffer asside for periods where the IWM moves against me. When IWM drops, the value of Puts grow exponentially. Margin requirements increase as this value grows and as the IWM gets closer to my strike price. I need a buffer for increased margin requirements. Without this buffer I would surely get a margin call in most months. This is bad because it would force me to close part of a position while it was down. I could only re-enter when the position recovered. My buffer is 25%. So, Risk Capital is 25% of Total Capital.
2) Average the underlying instrument’s (IWM right now) price movements into my trading by breaking my risk capital down into sements that can be traded in even periods within the average life-span of one posiiton. This allows all risk capital to be in play at any given time but also reduces the risk that the market moves against me immediately after putting on a position that might use all of my risk capital.
> IWM closed at 71.16, down .21 Friday.
> My short Puts in May at 58 (strike price) closed at 13 cents. I gained $3 per contract.
> For those playing along at home, the current margin required for this position is $883 per contract. Divide your risk amount (I use 75% of my account) by 883 and that is how many contracts you can sell.
> I am more than 12 strikes out of the money now.
> I now have a 98.29% chance of collecting all the premium for this month. (according to the model)
> The annualized return on capital (ROC) for this positon is now 13.29%. The calculation now assumes I close this position at 4 cents on 5/1/08. At this rate we will close much sooner than that. ROC is dropping because we collected most of the premium in the position already due to IWM moving up and implied volatility dropping. There simply isn’t much value left in the position.
> My expectancy is still 48 cents profit for every 1 dollar of premium collected.