Jason Calacanis, an entrepreneur and angel investor, writes about startups, investing, and tech companies like Apple and Microsoft.
HN links it mostly for his market warnings; one commenter cites his 'Winter is coming' post and points to a newer warning post.
"Winter is coming".
For a more recent warning, see https://medium.com/@jason/this-is-your-captain-speaking-im-turning-on-the-fasten-seat-belt-sign-a901eaa39f12