Of course not, please dont do it if you dont want to lose BTC value.
i want to ask,, Is good if i sell my btc and all in hold eth? give me advice
it is the worst thing that you can do, maybe ethereum has been rising a lot during the last months if we talk about USD value.
But just look at the charts, it was 0.12 bitcoins on June, and now it is just 0.04 each one.
It has rised a lot if we talk about fiat, but in bitcoins, it decreased more than 60% in about four-five months.
The best thing that you can do is just have that money on bitcoin, or just buy some eths.