No wait for BTC $20K+ rally -> ETH will dump and you will buy much cheaper!
How good was this advice to all those who wanted to buy at the peak, but unfortunately the greed and inexperience of many stalwart won. It is now possible to invest in Ethereum, and in the long term this investment will be more than justified.
For me, ETH is still the best altcoin in this market and investing in ETH is great. ETH is falling with the other altcoin due to the money being poured into the BTC but that is understandable and I believe ETH will recover quickly when things are more stable. ETH's current price is very good to keep in the remaining months of 2018.
But remember the fact that the prices of all alts depend highly on BTC price. If BTC goes up the value of the alts go up so it's best to pile up as many alts as you can and wait for BTC to skyrocket.