You can't follow them. By the time you learn what they're doing,...

You can't follow them. By the time you learn what they're doing, it's already done. Take this last CR, for example. The stock went into trading halt at the same time the offer went out to the "big end". The stock didn't start trading again until after the deal was done. Nothing you could have done about it.

Substantial holder notices can be lodged up to 5 trading days after the change, by which time the holder is probably moving in a different direction.

The "big end" rely on lots of holders "following" them so they can be harvested. If you try it, you're just going to get harvested too.