[M.K. Borders]

Thanks to all who answer.

[packrat35]

http://en.wikipedia.org/wiki/Uptick_rule

[50mm]

I'll give it a go. The "uptick" rule was instituted to prevent "piling on" a stock and driving its price down as more and more "shorters" sell. The rule says that when shorting a stock the sale must be at a price higher than the last sale executed. This means that the sale is executed when the stock price is on the way back up.