# Pre-open trading



## el_ninj0 (1 June 2005)

Can anyone explain to how pre trading works?, Ive just been MXG and MAP trade around 9 million shares before the market opens. Who can do this?, and by what means?


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## tech/a (1 June 2005)

*Re: Pre Open Trading*

If there are clients wanting to trade the same stock--one selling and one buying---using the same broker then a cross trade can be made at an agreed price.


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## RichKid (1 June 2005)

*Re: Pre Open Trading*



			
				el_ninj0 said:
			
		

> Can anyone explain to how pre trading works?, Ive just been MXG and MAP trade around 9 million shares before the market opens. Who can do this?, and by what means?




Hi EN,
Use the search tool, there are at least 2 threads on it from memory, some good explanations. Also see the www.ASX.com.au site for how the market works.


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## Battman64 (1 June 2005)

*Re: Pre Open Trading*

First day of the month
Pre Open Trading

I have just been informed:
CTX 2.5 mil
BHP 1.5 mil
NCM / CSR 3/400 k
Lots of others 200k

Information not confirmed as yet!


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## Wysiwyg (28 April 2010)

*Re: Pre Open Trading*

Just wondering if anyone can confirm an opening market price for two different prices with the same quantity and no other bids or asks in between or at these prices. Pre open is ....

Stock buy = 20000 shares @ 50c
Stock sell = 20000 shares @ 40c.

What is the opening price at auction?


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## skyQuake (28 April 2010)

*Re: Pre Open Trading*



Wysiwyg said:


> Just wondering if anyone can confirm an opening market price for two different prices with the same quantity and no other bids or asks in between or at these prices. Pre open is ....
> 
> Stock buy = 20000 shares @ 50c
> Stock sell = 20000 shares @ 40c.
> ...




ASX orders are price THEN time priority. If the 50c order came in first, it will match at 50c.


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## Wysiwyg (28 April 2010)

*Re: Pre Open Trading*



skyQuake said:


> ASX orders are price THEN time priority. If the 50c order came in first, it will match at 50c.



Can't find that anywhere on the "ASX Calculating opening & closing prices" site.

Do you have a copy and paste or reference please?


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## Wysiwyg (28 April 2010)

*Re: Pre Open Trading*



skyQuake said:


> ASX orders are price THEN time priority. If the 50c order came in first, it will match at 50c.



ASX description of the price match up states this.


> *If the Minimum Surplus for all possible auction prices is zero*, then the algorithm marks *the highest and lowest prices within that range as the potential* *auction prices* to be applied in this principle.




and then .... 



> *If the reference price is equal to or greater than the higher of the* *two possible prices* established in the first section of this principle, then the higher price becomes the auction price.



The reference price is yesterdays close price. In my example the prices overlap but there is no minimum surplus to break the deadlock. So this where it is hazy to me. I interpret this as having to use the "reference price" to break the deadlock.  


> *If the reference price is equal to or less than the lower of the two* *possible prices* established in the first section of this principle, then the lower price becomes the auction price.





> *If the reference price lies between the two possible prices* established in the first section of this principle, then the reference price itself becomes the auction price.


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