Yogi is an automated portfolio manager, liquidity provider, and price sensor.
Yogi turns the concept of an index fund on its head: instead of a paying fees to portfolio managers to rebalance your portfolio, you collect fees from traders, who rebalance your portfolio by following arbitrage opportunities.
Yogi is based on Balancer implementation of an N-dimensional invariant surface which is a generalization of the constant product formula described by Vitalik Buterin and proven viable by the popular Uniswap dapp.