Academic question Is it possible to refuse to give back the shares acquired on loan and shorted if the principal owner requests it, irrespective of margin call? For example, let's say you have shorted XYZ stock at $25, but it goes up to $35. However, the owner of the shares of whom you've loaned from demands the shares back. Must you buy new shares to fulfill the request even if you are capable of meeting margin requirements? The reason why is because if this is true then shorting has more imputed risk than otherwise long-only because of the uncertainty over the establishment of who controls the shares acquired.