I don't believe I have it backwards. Without trying to appeal to authority, I work in the industry and except in very specific cases where it is clear how much AUM a particular fund runs, people will quote percentage returns because it tells you immediately what is the severity.
I'm sorry but nobody can keep all the different AUMs in their head. There are thousands (tens of thousands?) of funds in the world, I really can't be bothered to memorize all their assets. The headline was clearly written to elicit an emotional response, at the expense of information content.
> Losing $3.7bn trading stocks in a tech bull-market the likes of which we've never seen is...not good, regardless of the fund size.
It's not good, but again the dollar figure is completely meaningless: if the fund has an AUM of $100bln, this is a largely inconsequential -4%, which may compare unfavorably to their peer group and may elicit management changes down the line. For a $10 bln fund this is pretty much game over and they would be gearing for a fire sale of office equipment.