1 aDAI is redeemable for 1 DAI at any time on Aave, still, the market price of aDAI in DAI is volatile. Since inception, the median price is 1 aDAI = 1.01 DAI. It is possible to redeem aDAI for more DAI in the markets than on Aave, representing an opportunity for users. In case of lack of liquidity on the protocol, users can exchange their aDAI, with profit on Uniswap.