It’s probably organic. It often happens that the HN front page coalesces briefly on a theme. People see an article on a topic, research it a bit, and post what they find (or just repost something they remember from last week). And similarly it gets more upvotes on the “new” page because interest in the topic is active.

There are a surprising number of Apple and Tesla posts lately. While I am not yet convinced it is being outright paid for, but there does seem to be a higher concentration of specific brand advocacy here than there used to be. I wonder if it has to do with so many people also being share holders with a vested interest in their success?