now Bitcoin price has increased 17.5% in the last 7 days and now the price is $27,750.69, then BTC Domination is 70.9% with Market Cap amount $727,677,130,354, but Ethereum price is currently $644.61 and is down 1.44% from the last 7 days, so I bought Ethereum with all my money (money that I use specifically for investment), because I believe Ethereum price will soon increase very high (bull run) following Bitcoin price movement and of course I will get a very big profit from investing in Ethereum (my target for Ethereum price is $1100-$1400), because I believe if Bitcoin dominance decreases, then it will make the price of altcoin increases (including the price of Ethereum).
I think you have the best decision in investing in etherium because etherium price now is increase. I also invested a little amount in altcoins mostly in etherium and i can say that i gain profits from it. And so to other altcoins that i invested i gain profits not that big like etherium but its ok for me.