CXXT are cross trades, spaced minutes apart aren't bot trades, merely desk to desk, and as the above example shows, drove the price nowhere. I think CXXT is superann. Small quantities like these represent index, EFT or other products that are weighted over the index they are buying. 1 contract of $500 is split up percentage wise over all the companies comprising that index, hence $36 on CXO whilst RIO may be weighted $150. Imagine all the super funds with all their various investments distributing the money. 1 share on LYC at 9.6c, etc.
Refer to http://asxinsights.com/case-studies/ for other anomalies where desks drive the price.
Bot trades scalp your buy/sell order in micro seconds, none of the above trades. Insider trading at its worst.
Also none of the above trades are algorithmic. These trades are highly conditional automatic trades that occur when the conditions are met: price top with doji hanging man, preceded by mother having a cup a tea at 1500 hours= buy at price of the falling % of the last 34 trades. Rubbish example I know, maybe have a look in the algorithmic thread, they are developing one.
