Choosing among equivalent trades


Thanks so much for your advice. I read through your blog and also did a simple analysis this morning. It shows clearly, as you highlighted in your blog and mail,  that Collar is equivalent to put credit spread as well as bull call spread.

In the option studies, I found it is difficult to determine which to choose (put credit spread or bull call spread) when entering a trade.

One thing I considered is: if I would like to buy the stock at lower price, I will go for put credit spread. Is it right?

Also, in spread, e.g. bull call spread, there are 3 types of options

  a) buy ITM call, sell ATM call

  b) buy ITM call, sell OTM call

  c) buy ATM call, sell OTM call

I have read several option books recently, none of them have given me a clear guideline. Your advice and thoughts are highly appreciated.



Hello Jack,

1) If you proved it to yourself that the collar is equivalent to selling a put spread or buying a call spread, why don't you believe the proof?

If the trades produce exactly the same financial results – and that's one requirement for the positions to be equivalent – why does it matter which you choose?  It does not matter – unless the markets are inefficient. That is a rare occurrence.

Unless you already own shares, avoid the 3-legged collar and cut trading expenses by choosing a 2-legged put spread.

Here is how to determine which to trade – and this seldom applies, but is worth checking.  Assume it's a 5 point spread and that you can collect $2.10 when selling the put spread.  If you can pay less than $2.90 for the call spread, then that is the spread of choice.

But – remember, buying means you pay interest on that $290 instead of collecting interest on the $210.  Thus, the call spread must not only be < $2.90, but enough less to compensate for the cost to carry the position.


2) 'Buying the stock at a lower price' does NOT depend on the spread chosen.  You wind up with a stock position only when expiration arrives and the stock is between the strike prices of the spread.

When you own the call spread, your long call is in the money and you exercise.  You pay the lower strike price.

When you sell the put spread, your short put is in the money and you are assigned an exercise notice. You pay the higher strike price.

To compensate for paying the 5-point higher strike price for the shares, you already collected the $500 difference when you sold the put spread instead of buying the call spread.  Equivalence!


3) The selection of strike prices is not something that can be  easily described.  When buying the call spread, you risk more, and can earn less when the options are in- or at the money.  In return, your chances of earning a profit increase.

My point:  You cannot just choose strikes based on whether option is at-, in- or out of the money.  Much more goes into the decision.


The term 'bull' is redundant in 'bull call spread.' 

  • When you buy a call spread, it is a bullish trade
  • When you sell a call spread, it is a bearish trade
  • When you sell a put spread, it is a bullish trade
  • When you buy a put spread, it is a bearish trade

2 Responses to Choosing among equivalent trades

  1. Donald W. 11/23/2009 at 7:01 AM #

    I clink on your link and it sends me back to same place.
    Listed below are links to weblogs that reference Choosing among equivalent trades:

  2. Mark Wolfinger 11/23/2009 at 8:24 AM #

    Cannot figure it out.
    Working on it