... also, a short sale doesn’t have a time limit. You can be short as long as you want. However, if prices go up, then the debt in your margin account also goes

... also, a short sale doesn’t have a time limit. You can be short as long as you want. However, if prices go up, then the debt in your margin account also goes up, and you might get a “margin call” - either deposit more capital, or close out some leveraged positions. Margin calls are the nightmare scenarios for short sellers, since they can force you to buy out at the worst possible time.