>I love the way I keep getting downvoted on HN whenever I say anything about a subject about which I know a lot more about than the average person here (usually investment and finance).

That's the inherent nature of these voting based online platforms. They reward what the user base wants to hear over what is correct. This is especially apparent in matters with inherent nuance and uncertainty.

Or, writing like a know-it-all arse isn't rewarded here. Being genuine and curious about things is rewarded more than if you're an obnoxious ass about how right you are.