In 2019 I think everyone will work hard to get back on the positive track. The market must be able to pump and thus will make Crypto again have great popularity. And what makes me sure is that in 2018 the market has collapsed and in 2019 this condition will definitely be reversed.
You have to pick the altcoin that has the best potential. Better if you invest in several good cryptocurrencies. Then you buy them and hold for at least 1-2 years. It is worth doing.