In addition, we have DanG, one of the best moderators around.
I'm very thankful for the good signal/noise ratio here, and try not to mess it up myself.
I'd say more precisely that we're blindly cynical, and that makes us pretty vulnerable to a certain kind of misinformation.
When I'm bored, I pay attention to the 'new' posts. There are a few users that are constantly posting the kind of cynic bait that HN loves, dated any time from the last 70 years. It usually doesn't do very well (as in ranking on HN), but sometimes it does. I can't say all of it is misinformation, but when I bother to check, it often does turn out to be grossly misleading.
If you look at ivermectin, it wasn't successfully pumped here. There were some honest, if remarkably silly proponents and they got pretty solidly whacked for optimistic ascientific thinking.
(Yea, that's a one sided take, but it goes to the general sense you can't just float ideas here and get lauded all the time)
As a non american I sometimes feel there is a strong Ayn Randian libertarianist rump writing here and I suspect it's people seduced by the bubble, with high net worth justifying their privilege. There is also a fair bit of anticommunist fervour, most notably anti CCP. Given who would use this channel for disinformation, I think you can argue it's not libertarians, or the CCP. So who does that leave? Disinformation typically advantages somebody. If it's not these people then qui bono? The CCP? Russia? I can't see it. They have better channels to dis-inform in.
I don't think HN is particularly pro Trump, or pro Theil or pro Cryptocurrency. Or pro Biden. It is often anti. That makes it seem unlikely it's being used to push stocks.
Basically, noting the other comment that politics is usually frowned on (my bias is showing above btw)
I can't see where the dis Informed people are securing a benefit beyond humour and if this is just an illuminated fnord view of the world, then at worst it's harmless.
For any US citizens, that bias is invisible. For non-US citizens, the bias is very visible.