I find that many people have a habit of holding ETH, BTC, altcoin for a long time and always hoping that it will rise again. If you are a trader, you will lose money for that. Set small target and sell them when you see profits. I only need 3-5% profit when trading.
If you see the market going down, stop loss before it's too late. You may lose 5-10% of the capital but when the market goes down you can buy more btc, eth when you hold btc, eth, altcoin.
Sell all ETH, BTC into Stable Coin when the market goes down
I think it's better if you will only sell half. Thus, you're still able to gain profit if market bounces from its bearish market to bullish market. However, if you really don't want to risk something, this would you do.
No it is not good to sell even half at this time, price is on progress and it will recover very soon so not good to sell for now, hold your coin and wait patiently, as an experienced investor I would only suggest all of you to keep holding because it is on bearish soon bull will start moving, price will recover within few months but patience is key to success.