Anyone who makes it on to trending has their reputation boosted as a result. A new user could post something big, end up on trending have have a reputation of 6 the same day.
Those with reputation of 7 or 8 have it the trending pages multiple times.
Better to look at 'hot' for new people to promote.
Ah! Got it. Thank you for the clarification.
Actually, I had to scroll to the 28th 'hot' post to find the first score below a 7.