Glossary A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 1 | 3 | 4 | 5 Definitions by InvestorWords.com   What is...? sell short A sale in which the seller has borrowed a security (or commodity futures contract) from a broker and sold it, with the understanding that it must later be bought back (hopefully at a lower price) and returned to the broker. SEC rules allow investors to sell short only on an uptick or a zero-plus tick, to prevent pool operators from driving down a stock price through heavy short-selling, then buying the shares for a large profit. also called selling short. see also borrowed stock, called away, hedged tender, lending at a rate, members'short sale ratio, sale, securities loan, selling short against the box. Copyright ©2009 by InvestorGuide.com. All Rights Reserved.