I agree, “Show HN” should work, maybe with some standard way of indicating that they’re interested in investors contacting them.

No, I meant that investors post about themselves, in what they're interested etc. and startups can contact them :-)

Haha woops, I think having the startups present themselves would be better because they have more relevant information and I think potentially having multiple investors looking at a startup at once would help create pressure for them to actually invest.