Player concentrations on ratings multiples of 100

So I don't know if there has been a thread about this before but I'll do it anyways, couldn't find one. I recently got to 1700 bullet(which I'm not even remotely proud of, I'll probably stop playing bullet for some time now for the sake of my chess) and I just looked at the weekly rating graph.

One really odd thing that stands out is how there are little "peaks" of players on ratings that a multiples of 100s. At first I thought it was just my case, they reach the rating and stop playing, but it wouldn't make much sense if the graph is updated weekly. So, what do you think?

Actually, your first guess was likely correct. People tend to set their milestones at round numbers, which would explain the peaks in the graph. The graph being updated weekly doesn't really change anything, because there are people reaching their milestones weekly.

there have been multiple threads about this.
people grinding for the next hump and sitting idle after achieving a certain milestone cause those peaks as #2 pointed out. you can see the 2000 peak is a bit larger, coz its a nice round number. some people try to reach 2000 in as many time controls and variants as possible.