If Ethereum's supply is infinite, why does it enjoy a $112 billion+ market cap?
Ethereum coins is always the coin that is being used of ico's to scale the value of their altcoin and because of that, eth coins become more popular and different traders are usually exchanging their coins to eth and hold it for a very long time.
However, ethereum doesn't have a coin, it's called a token instead. When you said it as a coin, it sounds ridiculous. I recommend you to find out more about what is token and coin.