Let's take an example of an imaginary Mr. Ayo who provided liquidity of $1k Bitcoin and $1k USDC. If Bitcoin were to double in price, the total assets in your Pool would total $3k. With $2k in bitcoin and $1k in USDC. If you think this is the case, you are a bit wrong. What Uniswap does that it will constantly rebalance the assets, so it would have to sell bitcoin for USDC to reach the equilibrium again, meaning you will have $1.5k Bitcoin and USD 1.5k (not considering transaction fees). In simple words, the change in the price of any of the tokens will cause a rebalancing.  Since the price of both tokens is not the same, you could lose out on huge gains Because of the rebalancing.