When a particular market is moving upwards or downwards in terms of its price.
Uniswap V2 fails to keep liquidity providers profitable in a trending market, in both cases of uptrend and downtrend, Liquidity provider faces an impermanent loss which scares them away.
Uniswap V3 allows liquidity providers to provide liquidity from a single token by maximizing the impermanent loss, For an uptrend on an ETH-USDT pool, the liquidity provider has to provide ETH, which will get converted to USDT after the price range has reached. Also Liquidity providers have to select a price range to increase their exposure of funds else they can be left out.
YNOT finance makes things better for liquidity providers by allowing users to provide liquidity using a single token but by eliminating impermanent loss as for on an uptrend on an ETH-USDT pool, liquidity provider has to provide USDT and for downtrend ETH. Here if the market goes up user will have more USDT and if market goes down more ETH. Also the position will be open irrespective of any price range and every liquidity provider gets the same exposure just with a different impact on the funds.