See https://news.ycombinator.com/leaders. Way more than 100, almost certainly more than 1,000, and very likely more than 10,000 if my guesswork based on those figures is correct.
I used http://hn-karma-tracker.herokuapp.com/ to find the number of users with a karma over 927, and there are 5k. There are probably about 4-4.5k that have a karma over 1000, and that includes users that are no longer a part of the community for whatever reason (like aaronsw.)
