I doubt the CDY share price movements will be a surprise to Eck, who will be well aware of the computer games that are now continually played on all global stock markets. In no way are they specific to Australia or to CDY.
Regulatory approved practices such as HFT and dark pools are designed to target that class of shareholders who are excluded from participating in them. What is surprising is the time it takes for those targeted to realise what the game rules are, and in the interim substitute imagined conspiracy theories as an explanation.