Since the Q2 of 2020, Defi hypes have been going all over the Crypto spaces, some made people huge profits, while some exit scam. Defi is just coined from the word "Decentralised Finance". It is a pivotal part of cryptocurrencies since it's adoption. Some of the most successful Defi projects this year are Oikos, DIA, Lend, UNI and a lot more.