Hey there! Not sure why everyone is so negative. DeFI is obviously decentralized finance. We all know it would be "Better" if on BSV etc but it has gained a lot of interest. It is basically figuring out new ways to do old financial things using the blockchain and tokens etc I am going to link a great article below but this is essentially their summary..
"Imagine a global, open alternative to every financial service you use today — savings, loans, trading, insurance and more — accessible to anyo