It's called stopping lose, this is what USDT and other stable coins are good for so yes it's a good move to safe you from loses, if you are into crypto for long term I suggest you hold USDT because once in a while opportunities like this will always come
Yes many trader's now always preparing to have USDT to hold not for investing . But in the right time like this happen ,when the price decline faster then this is the right time to use the usdt and buy btc in the bottom this things will give you upto 30% profit easily with that market movement.