I can confirm here too that buying on Bittrex i'm able to see my holdings on the distribution graph.

If you have a look at the VTR rich list - the ~850k holder isn't in there:

http://cryptoguru dot tk/RichList/index.php?Currency=VTR

There is several explanations for this - but I'm assuming this just means Bittrex must spread out the VTR that they hold on the exchange across multiple wallet addresses for security reasons.