Hope your coffee wasn't too hot. Two reasons - (1) inflow of more money from institutional investors and, (2) positive sentiment regarding regulation from the SEC.
The first bitcoin futures launched in Dec 2017 put over 10 billion of institutional money into bitcoin; unfortunately though, bitcoin was at an ATH at that time and most of that money was used to short bitcoin. Now bitcoin is at the bottom of the correction hence money from the ETF could be used to load up more coins to ride the bull.
The main difference between futures and ETF is that only big players can buy futures because of the size of the contracts. ETF, on the other hand, are like stocks so anyone (small and large investors) can buy into bitcoin at whatever amount.