What does commingled storage mean?
In commingled storage the depository holds identical products together: all clients' one-ounce Gold Eagles of a given type in one pool, for example. Your account records show you own a defined quantity of that product within the pool.
Your ownership is fully accounted for, audits reconcile total holdings against all client records, but no specific coin is earmarked as yours.
Why do many buyers choose commingled?
Cost. Pooling identical product is more efficient to store and administer, and the depository passes that efficiency on as lower fees. For standard, highly liquid bullion coins, the piece-level specificity of segregated storage adds little practical value.
The trade-off appears at withdrawal: you receive the same product and quantity, but not necessarily the identical coins you sent in. For fungible bullion, most buyers consider that irrelevant; for serialized bars, many do not.
How does commingled storage show up in practice?
Check the storage agreement: it will state whether holdings are commingled or segregated, and the fee schedule will reflect it. Neither is inherently better, the right choice depends on what you hold and what you care about.