Hello I dont understand I bought for 4000 Eur one hour ago of Ethereum when it was going up, it stayed around the 10-20%, it started to decrease 5 minutes ago so I sold it and now cex.io just gave me 3500eur for it... wtf... 
The %came from me watching livecoinwatch.. Cex.io doesnt have the accurate price ??
I think that you failed to enter the trade because you chose the wrong time of the trade and have no specific plan when starting to trade. In addition, you need technical analysis skills and market intelligence in order to make the most accurate market judgments. You need to stumble many times to be able to draw experience for yourself.The %came from me watching livecoinwatch.. Cex.io doesnt have the accurate price ??