For example, if there are 300 DAI.e, 500 USDC.e, 400 TUSD and 700 USDT.e in the AS4D pool, you will need to pay a premium to deposit USDT.e and you will be given a reward to deposit DAI.e. The exact same mechanism is also applicable when withdrawing from the pool. Given the above example, you would pay a fee to withdraw in DAI.e and be rewarded for withdrawing in USDT.e.