That's a bad faith exaggeration argument you just made: we don't need to know everything someone has financial interest in, just if it's related to the topic. It's why VCs, for example, if writing a blog post about a company - they will write a disclaimer that they own shares in the company. We have laws to require people to disclose if something is sponsorship as well - because it changes the value of what's being said.
> we don't need to know everything someone has financial interest in
You wouldn't. You would just know that OP owns GOOG if the article is about GOOG. Only HN/the brokerage would have their entire portfolio.
> It's why VCs, for example, if writing a blog post about a company - they will write a disclaimer that they own shares in the company
As far as I can tell this isn't a legal requirement - shareholders have no obligation to disclose their position, even major stakeholders don't have to do so every time they post about the company - it's mainly to protect the writer's reputation and because they really don't want to mislead the reader. The point is that HN shouldn't be the one keeping the comments and submissions free of articles posted "for the intent of manipulating the market" regardless if we're talking about crypto securities or public securities.
"As far as I can tell this isn't a legal requirement - shareholders have no obligation to disclose their position, ..."
Very much seems like this should be remedied, it's part of integrity for people to know if you have a financial motivation behind what you say - at least if you want a society that has integrity and not as easily open to manipulation; it's ultimately why advertising is bad, the people didn't deserve to get the attention they've getting - and why in part Tesla has done so well - they created a good enough product to get word of mouth and receive the attention they deserve (for the good and bad) to receive.