I posted this some time back....please to see some else is finally realising the game
I found this on Wikipedia when looking up HK stock exchange, perhaps ASX punters are a bit slower then our asian counterparts...perhaps they(HK)are doing it here and we don't even know about it. ------------------------------------- The closing price is reported as the median of five price snapshots taken from 3:59 to 4:00 pm every 15 seconds.
In May 2008, the exchange also implemented a closing auction session to run from 4:00 pm to 4:10 pm, with a similar pricing mechanism as the opening auction; however, this resulted in significant fluctuations in the closing prices of stocks and suspicions of market manipulation. Initially, the exchange proposed limiting price fluctuations in the auction sessions to 2%; in the end, they removed the closing session entirely in March 2009
source: Ng, Katherine (2009-03-13), "HKEx scraps closing auction", The Hong Kong Standard, http://www.thestandard.com.hk/news_detail.asp?we_cat=11&art_id=79490&sid=23085832&con_type=1&d_str=20090313&fc=8, retrieved 2009-06-05
