Whatever You Like Paper Trail T.I.

rubberband banks in my pocket

Fat stacks of bills need a sturdy rubberband to keep them together. Since gangstas carry loads of cash, the conventional money clip fails, therefore the expandable rubberband must be employed.
people carry around folded-over, rubberbanded stacks of bills in their pocket, because they either don't trust actual banks or it's more convenient to cash their paycheck and carry the money in their pocket