I've noticed that the little trending arrows only seem to work for about 3 or 4 people at a time. I mean, our positioning is all random so I'm not sure what they are even for, maybe just for fun? Any way, just pointing out that 90% of them are just gray and not doing anything.
Each refresh round (10 minutes) the data gets fetched. After all data is stored in the database, it analizes the new values regarding bestshare and will create a new ranking. The arrows indicates the change in comparison to the ranking on the last refresh (10 minutes ago).
Example:
On this image, Sascha has had a new bestshare value. Compared to all other racers, he jumped from rank 11 up to 2. The bestshare values of all people from quer85 to Ant77 dind't change, but they all loose one rank, because Sascha is now on rank 2.
On the refresh before the last refresh, Sascha was on rank 11, so everyone after him isn't affected by this change in the ranking and their arrow will stay gray. That could occure on every place in the ranking, with the most people moved, but some always wont have a gray arrow, because their rank didn't change between the two last refresh rounds.
It only changes something in the ranking system, if at least one bestshare is not the same anymore compared to one refresh before. And if there is a change, the trend of all racers will be adjusted.
If someone has a better idea, I will try to implement it
I have been playing around pushing up the Frequency and trying to work out what the incompatibility is with the R1 and higher frequencies on solo.ckpool that does not seem to be there on any other Site. 
And I'm sure Ammi don't want to delete all the stats entries in the database.
