For altcoins that have achieved ATH in 2017, I think it will never return, this market has dropped a lot and if it increases again, I think only altcoins appearing in 2019 will increase.
Most altcoins are experiencing a huge discount and consecutive adjustments have made it difficult for altcoins to grow steadily this year. I think now any investment will be risky so instead of investing you should learn some new knowledge to prepare for the new phase in this market. I believe that this discount will end soon and those who have knowledge of altcoin will know what to do next