That is due to that fact that last 24 hrs trading activity went below $100 USD.
It is consider low volume, once anytime if last 24 hrs trade reaches over $100, it will be back to Top 100.
But more important right now is getting us on CEX, looking at so many other coins listed by them. they all able to collect close to 1 BTC.
It is way more important than the ranking, once it gets listed their lot more traders/buyers will invest in VC. The current exchange does not have any traders. It's only helps us in ranking.
I urge all to consider spend BTC on voting instead of trading (https://www.coinexchange.io/market/VC/BTC)