To know what a BTC ETF is, you'll have to know what a traditional ETF is. This video explains both (albeit a few months old): https://www.youtube.com/watch?v=OwpFBi-jZVg

This new buzz can very well be the reason for a price increase seeing as it will allow crypto to be more a accessible for the masses or generally people who have been on the fence due to concerns about traditional exchange platforms, wallets, etc. People like convenience and this is about as convenient as it gets in regards to investing (if approved by the SEC, of course).