"Still, why so many orders of this type in the last few weeks,

where previously there were none?"

IMO the fact ARU is now in various indexes accounts for the change. There are a number of pro traders who are forbidden by the brokers they work for, to trade in stocks that are not included in certain TSE indexes. Now you have these new players who are trying to make a buck day trading. If they see an opportunity late in the day to make a few cents they will try & take advantage.

Regards

Joltin