Although I don't completely agree that CBA being a substantial...

Although I don't completely agree that CBA being a substantial shareholder suggests a trigger to buy AIO (they also have/had substantial holdings in CNP, ABS, just to name a few)

However in this case, they have made the right decision as they see the LT potential here.
In the medium term, AIO is forming higher lows on the dips.

Current secondary uptrend suggests a 'Hold', or trade the peaks and troughs if you're smart enough to get the timing right.
my opinion only - dyor