By | November 23 2012 10:00 AM

Research In Motion (NASDAQ: RIMM [FREE Stock Trend Analysis]) shares are up more than 10 percent on very heavy volume (more than 2.8 million shares have already traded) in pre-market action Friday. The upside follows a 17 percent move higher on the Toronto Stock Exchange Thursday. While a number of sources are attributing the strength to a bullish research note from National Bank's Kris Thompson on Thursday, this is certainly not the full story. Thomspon boosted his price target on RIM shares from $12 to $15 amid increased carrier optimism related to BlackBerry 10 -- a factor also cited by Jefferies' Peter Misek Tuesday morning when he upgraded the stock to Hold. RIM shares were up nearly six percent on Wednesday.