Currently I own a lot of altcoin, I bought them at ico. My account is being downgraded several times. There are many people who say bitcoin will continue to decrease, so altcoin prices also decreased compared to USDT. So now, should I sell them and wait for the price to buy back? Give me advice 
in this situation we need to invest something because holding is not done by everyone in the previous time but right now the value of everything is improving if you don't invest now then you will feel after some months because at the time the value of every investment was little bit higher