The downtrend will stop if people stop selling their hold coins, especially Bitcoin we need to look for the bigger picture here if it isn't for Bitcoin other Altcoin will not establish a good position it is all thanks to the father of cryptocurrency that ETH right now is holding on its own, but maybe some other news that would feature Ethereum will suddenly increase a slight price for Bitcoin.
And if you see most Altcoins out there they are connected to Ethereum Blockchain so maybe an unlikely sudden pump will be made if it just holds its price just still, But I doubt that will happen A movement for Altcoin sometimes is just for Altcoin only but Bitcoin sudden movement will surely change the altcoin price as well.
It seems impossible to expect crypto users to stop selling their coins. trade will be alive if there is a sale and purchase transaction, if no one sells, the bid will definitely be higher. and the reason they sell their coin collections is to want to get wealth, and because of that they always sell their coin collections on a regular basis. and when they reach a low price, they will buy back, so the trade will look more stable.