I don't think this is true. I trade cross currency basis and if there was excess demand for offshore USD the "basis" (premium over normal rates to borrow USD in

I don't think this is true. I trade cross currency basis and if there was excess demand for offshore USD the "basis" (premium over normal rates to borrow USD in return for lending e.g. EUR ) would be moving dramatically. It changed a bit today in response to USD shortage but this seems predominantly a domestic story.