Trending Oddity.

Strangely, while viewing the Halo forum, I noticed this topic trending from page 4.

http://www.2old2play.com/forum/divisions/halo-series/halo-4-regarding-de-scoping-comments-e3-496865

Then I went to Off topic and it wasn't trending at all. Returning to the Halo forum, I found it trending again.

Explanation please. I'm confused.

UPDATE: The oddity became less odd when the trending list stayed the same after moving between forums. I'm not crazy, not crazy, crazy.