Hi
Depending on the way of trading, we have to choose one or more option we want to trade with. We now have an idea about what an option chain is and how important it is to choose the right option month on the underlying we trade on.
Now knowing that: The next step we can do is to have a look at the Open Interest (OI) on important option strike levels. What ever kind of option trader you are, you will first check the vola in the market which gives you an idea about the range the market moves and you will check the time frame you want to be in the market.
If vola is low and you prefer to do directional option trades, you can use options deep in the money, as they represent in a better way the moves of the underling. Why? Because the Delta (*)of the option is higher and if vola of the market is low, the market moves less. If you choose an otm option, this option may never comes in to the money. So you then choose your option strike levels build on that fact.
If vola is high, you also could use otm, as market moves fast and your option could get atm or even itm quit quick. But as I told: Could and not must. Also here, you then would choose an option strike level based on that fact.
Definition of open interest:
The total number of options and/or futures contracts that are not closed or delivered on a particular day. A common misconception is that open interest is the same thing as volume of options and futures trades. This is not correct, as demonstrated in the following example:
-On January 1, A buys an option, which leaves an open interest and also creates trading volume of 1.
-On January 2, C and D create trading volume of 5 and there are also five more options left open.
-On January 3, A takes an offsetting position, open interest is reduced by 1 and trading volume is 1.
-On January 4, E simply replaces C and open interest does not change, trading volume increases by 5. (**)
Now what is it useful for to have a look at this OI? OI tells me, if this option is asked from other traders. If there is big OI on certain levels, we know that these strikes are asked for and we easily can buy and sell these options.
If there is very low OI on certain levels and we choose those strike levels, we really can get in trouble to trade with this option. As there is not much interest on such levels and we may own options from it, we could lose money on this options only because we not can sell them or buy them back, as there are no or only a few traders interest in this option. The bid ask spread (***) will be very bad and so we not need to choose such option strike levels.
Many try to predict the market through analyzing OI. If OI raises on certain strike levels, this is valued as a signal that the underlying could move to that strike levels and if OI falls, that is valued as a signal that market could move away from that levels. This analyzes is done on both sides, means on the call side and the put side. This knowledge can be quit useful in day trading and longer term trading. Kiranjakka has a thread in which he gives examples how to analyze this OI in your home market. Columbus, Linkon and others also have threads with lots of information on OI trading.
If we do strategically option trading and we want to implement for example a long strangle, like showed in post 44, we have to choose more than one option strike level. A simple way to choose this strike levels is the following:
One way to choose strike levels is to use the bell curve or also called the normal distribution and the OI for the strikes we choose.
If vola is high in the market we trade, we get automatically a bigger range and if vola is low, we get automatically a smaller range in the bell curve. The bell curve we use on the time frame we want to be in the market. Do not use the BC on a one hour time frame when you want to have results on a five day time frame.
As we now know the strike of the put and the call from the result of the BC, we check the OI on those levels. If they are good, we use those levels for our long strangle trade. If you do not know what the bell curve is, please read through the link given at the end of this post (****). Most important is to understand the following:
The Empirical Rule
The empirical rule is a handy quick estimate of the spread of the data given the mean and standard deviation of a data set that follows the normal distribution. The empirical rule states that for a normal distribution:
• 68% of the data will fall within 1 standard deviation of the mean.
• 95% of the data will fall within 2 standard deviations of the mean
• Almost all (99.7%) of the data will fall within 3 standard deviations of the mean
Note that these values are approximations. For example, according to the normal curve probability density function, 95% of the data will fall within 1.96 standard deviations of the mean; 2 standard deviations is a convenient approximation.
With simple words:
68% of the whole range is touched most. That is Standard Deviation one in the middle part of the curve. Both other Stdv, two and three, are looked at as support and resistance levels, which will be less touched mathematically.
This curve you can lay over any time frame you trade with. It will show you in what range market most likely will trade in this time frame. If we know that, we for example can place limit orders which have a chance to be filled, because of the math we used behind the strike level we place an order on. Check in your software if you have such a math tool and if not, paint ranges in your traded time frames to have an idea about any range which market maybe will trade.
Seventh subject closed
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DanPickUp
(*) Will explain more about Delta in the next post
(**)Source:
http://www.investopedia.com/terms/o/openinterest.asp
(***)
http://www.investopedia.com/terms/b/bid-askspread.asp
(****)
http://www.netmba.com/statistics/distribution/normal/