I think one of the things that goes unmentioned in these discussions is that while the US gets a lot of attention for this kind of activity, it has also (historically) been in the forefront of criminalization and prosecution. I may be wrong, but don't know of any other jurisdiction that prosecuted insider trading before the Eighties, and the US has had a pattern of investigating and regulating this since the 30s.

I don't think that this is a particular form of exceptionalism, beyond the US having a longer tradition of widespread, retail-owned shares, and law-making around that fact.

But sometimes I wonder when people are criticising the US as a culture, they're often choosing as the baseline that should be respected standards that were also defined in a US cultural context. What this sometimes means is that in internal US culture these points are seen as something that is heavily discussed, because there was a point where it was democratically decided and therefore could be undecided in the same way, like corporate personhood, or money-as-speech. In the case of the criminalization "insider trading", there is lively debate about whether this is actually a "good thing". That can sound horrific externally, because of course insider trading is a bad thing. But someone decided to make that a bad thing, and -- for historical accident reasons -- the edges of that debate was largely defined within the US.

(This is mostly just barely-informed speculation: sometimes issues like this emerge in international fora, or start in another culture and quickly spread. But the cultural and financial dominance of the US in the last century or so really makes these things often a point of debate in American terms, and a fixed point elsewhere. I speak here as an immigrant to the US and also someone who is dipped in global policy work, rather than someone who is stating this as a good or a bad thing.)

A lot of the United States historical influence and soft power comes from it being a nation of rules and laws. The credibility of the country provided a perception that it was a stable place to store value (investment in treasuries, greenbacks, etc). When the government is facilitating insider trading out in the open (repeatedly), we’re losing a lot more than money due to fraud.