The problem for shorts is they cannot just wait it out. Once some of the shorts try to exit, it will cause to SP to rise. This in turns will cause ALL other remaining shorts to fill the required margin with pure cash. They do not have on option of saying yes or no - the ones that are not to come up with required cash, get liquidated automaticaly - it means that their existing cash is used to buy the shares at current prices. This causes the SP to rise more. And short margin accounts demand even more cash, and more shorts are unable to come up with it, and thus more forced buying at current price, and even higher SP .. rinse and repeat until there are only shorts that have enough cash to pour into their margin account at some skyhigh SP price. Higher the SP, fewer such shorts. Longs have no trouble just waiting, shorts on the other hand must pay hard big cash for the wait. Some will be able to do it, many many many will not. This is about tens or even hundreds of billions of dollars of cash. Such money is normally invested elsewhere and not ready to be transferred at short notice as demanded by brokers managing the shorts.