Normally it is good to invest in something when its price is quite low and then sell it when it rises. But I think there is something strange with Ethereum. There are some issues going on with their code which needs to be resolved before 2019. Otherwise the entire market is down and Ethereum is a great coin. Yeah this is true that it is one of the most undervalued coin as of now. If it goes back to 1400 it will be like a 7 time return on a very safe coin.