From HN’s FAQ:<p>> There are no down arrows on stories. They appear on comments after users reach a certain karma threshold, but never on direct replies.<p>What’s the threshold? Can the threshold change?
When last seen it was 501, I think.<p>Just out of curiosity, did you try searching for the information? It's pretty easy to find:<p><a href="https://hn.algolia.com/?query=downvote%20threshold&sort=byDate" rel="nofollow">https://hn.algolia.com/?query=downvote%20threshold&sort=byDa...</a>