Imho is the most confident and reliable page that exists on the web.
Heres the link:
https://coinmarketcap.com/
This page will help you to know all about the price, currency, and quotation of absolutely all crypto coin that exist.
Like at this moment, when a few days ago the most important coins, altcoins and any other existing, went down on their prices, one of the reasons was because of a reunion of the G 20 Group, with an agenda of giving a legislation to relegate all about cyber coins, blockchain, trade and cyber market.
After this reunion, the prices have gone skyrocket again, and thanks to this page we all found out about this and started to invest again.
So my recommendation is to take a look at Cryptocurrency Market Capitalization keep yourself informed about the market, fluctuations, ups and downs.
Knowledge is power