Yes Uniswap is the biggest DeFi, but it's just a DEX running on Ethereum, I'm not really sure about the use case of UNI, cause last I checked it was just an airdrop coin I don't think there's any real usecase for it, but it's still a good investment, but I would recommend you check out coinmarketcap.com and select some good altcoins that have real usecase eth, atom and tron, cause all this coins have dipped during this correction, it will be a nice time to bag some of them.