It's not about the value it's about the strange amount of volume. Someone buying that much stock, that quickly, on no news... there's always a reason. Don't kid yourself. ASX were fair to question this. If it was legit buying it would have continued today.
Clearly, the reason wasn't what you are implying. Today's trading proves that. Someone who knows what they are doing will buy slower than that to keep the price down and not make it obvious...unless they want in quickly where there's usually a reason why...
PIO Price at posting:
1.5¢ Sentiment: Hold Disclosure: Not Held