This isn&#x27;t entirely true. If you hold securities in a margin account, your broker can lend the shares out to another client of theirs to short. You have no say in the matter. It&#x27;s up to your broker  to balance the number of longs vs shorts internally. But you can most definitely short on day one. I&#x27;ve done it and my account balance only has 1 comma in it.<p>If the short to long ratio gets too close, they will close out shorts or try to borrow from other clearing firms so that they don&#x27;t end up naked. Early on, most firms will just close the short.