Definition
Assets Under Custody – A retail-brokerage metric summing the fair value of every equity, option, cryptocurrency, and cash balance held in customer accounts, net of margin balances owed back to the platform, as of a given date. Grows from two sources — net new customer deposits and market price gains on what customers already hold — so a rising AUC figure during a bull market can overstate how much of the growth is actually new customer acquisition versus the market simply going up. Found In: Operating metrics disclosure (not a financial-statement line item)