[sosull]

With only a passing knowledge of the field, I'm aware that the standard of monopolistic effect varies between the EU and US (neither specifically uses financial size as the standard). In the EU it's about whether there is sufficient competition in the market, whereas in the US it's about whether the price is sufficiently competitive.

[int_19h]

In US it's basically "whether there's harm to the consumer", which is so nebulous that large monopolists can often successfully argue that their abusive practices are a net benefit (usually by arguing that prices are lower).

It wasn't always like that, though. We used to have antitrust with serious teeth in this country. And then it literally got borked: https://en.wikipedia.org/wiki/The_Antitrust_Paradox