Depends on the balance, but I could see a tiered monthly subscription model working well. So, if I have $10,000, my monthly fee is relatively low or just free,

Depends on the balance, but I could see a tiered monthly subscription model working well. So, if I have $10,000, my monthly fee is relatively low or just free, but if I have > $1M that fee goes up. Could be a percentage with a ceiling or an annual cap. Could just package it as Priority Withdraw Guarantee and charge it as an add-on and part of the guarantee is that your cash will be kept in a reserve independent of investment activities.