i want to ask,, Is good if i sell my btc and all in hold eth? give me advice
Putting your egg in one basket is never wise. That is a basic rule in investing. Eth is agreat coin and has a huge potential in the future but if you put it all in ethereum it is very risky.
You can always buy 2-3 coins and hold them for long term. Btc, eth , ltc, dash, monero are some of the great coins that can be hold long term.
it is not a good idea cause we all know that if that may dump you have nothing so better to have another than of that just like in ethereum it is much better having some coins also that you are trying to hold for i believe that there is a lot of coin there that are having a potential too.