I just saw some crazy numbers on coinmarketcap..
like $8500 btc, -90% vechain, +20% eth..
wtf is going on??
Not much for you to be alerted on that way. This is just a simple problem with index which can really give out those crazy numbers but not totally or we can conclude that its being hacked
and besides Coinmarketcap do give out a notice on about such issues and besides even if its hacked changing prices wont really be have a big effect yet this is just a preference site though.
For now anything works fine and i do still use up this site for checking out prices.