After the yfi hype the other project expect to beat the current price and issuing a token less than a million supply. They launched their own system to earn from farming a token with collateral. Lot of investors are lossing their money  and mostly some defi exit scam.

 This one is an example https://t.me/YFBULL smart contract https://etherscan.io/address/0x7dDd361DCa760C20657f80c43CD9c27440e5Bd06#internaltx

Probably 6 months before the yfi was in the bullrun from what the called (y) project as a defi  was become lame.

Their strategy is to airdrop a token to get more attention to everyone with huge referral rewards.