I dont think the volume has been exceptionally high.
Most stocks have an average daily turnover of around 0.3% of market cap, typically fluctuating up to 1% in a normal month. With a surprise negative announcement a daily volume spike to 10% is not uncommon, especially for a small cap.
On average, AMU has turned over around 0.7% per day since reinstatement in late Dec 2010, which is high but that high - particularly given it has been attractive to day traders in the 22.5 to 23c range.
It is more likely general market disappointment (as presented in the flat share price following the partial asset sale) that has led to the takeover offer.
AMU Price at posting:
22.0¢ Sentiment: ST Sell Disclosure: Held