The stock of Waterloo, Ontario-based RIM closed up $1.39, or more than 10 per cent, at $14.70 on the Toronto Stock Exchange. That's the highest point for the shares since April 2012.
The BlackBerry 10, due for release at the end of this month, is seen as a make-or-break product for RIM, which is trying to recover market share lost to Apple iPhones and Google’s Android operating system.
About 25 per cent of RIM's 524 million shares outstanding on the Toronto Stock Exchange and New York's Nasdaq are held by short sellers, which tends to make movements volatile.
These investors have essentially bet against RIM's success and lose money when the company's stock goes up. But they can also help drive the stock price up when they rush to cover their positions.