I am an Ethereum fan and I also invest in Ethereum, but I saw Polkadot price increase very high and now Polkadot is in the top 5 on coinmarketcap, so in your opinion in the next 7 days, which price will increase very high? Ethereum or Polkadot?
if I personally would definitely choose Ethereum

Polkadot is a very new projects compare to Ethereum blockchain. Any new projects could rise by any kind of hype.