It looks like all altcoins dump 10-20%. What is the reason? 
I am very sad 
I am very sad Exactly, I also very upset about dumping all Altcoin. So, I wanna ask the same question. Every coin is dumping so low day by day. What's the reason behind it? Already I have losses so much.
Bearmarket. It is normal. One day it will raise again. Maybe next month maybe in 2 years.
But everytimer the same, after bullmarket comes bearmarket and than again a strong bullmarket.
Loosers are only the guys which are refreshing every 5minutes their browser. They get panic and dump all holdings. Than the breakout starts and they buy higher back.
Next day red again and they sell and than green and they buy again higher back.
I for example buying when everything is red and holding as long as i dont need the money. For now I am only buying since 6 years.
I have maybe that much alts and btc that i dont need to buy more but i like it to invest smart.