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.
They dont. Bittrex wallet is most probably on the rich list somewhere. And of course bittrex has its own rich list called distrabution which shows you how many coins people are holding on the exchange.