It's an institution extricating itself from a position that's...

It's an institution extricating itself from a position that's too large to do as a bulk sell because it would send the price into a dive - so it bot-sells it off in small increments, slow dripping it into the market

... but by the frequency of these bot sells, it looks like they're in a bit of a hurry ...

No commission because they have their own trade floor.