Chris Lau, Kapitall: Blackberry (BBRY) shares are struggling to move higher, ahead of earnings on March 28, 2013. The open short position (by February 28) was 147.2 million shares, up 8% from mid-February. [Why is Good Friday A Stock Market Holiday?] The jury will be in after Blackberry reports its quarter: either short-sellers will be squeezed, or investors taking a bullish position will be validated. Since the reported quarter will only include the starting sales figures for Blackberry 10, management outlook on sales for the next quarter will be in focus. The keyboard-based Q10 is already anticipated. Sales levels for the older Curve, based on OS7, should be watched closely. Android-based devices and phones from Nokia (NOK) are vying for market share in the lower market segment. Bullish Case A weak start in the U.S. market does not invalidate the bullish case. Blackberry merely needs to succeed in the UK, Canada, EMEA, and Asia to sustain strong profit margins. App development is growing. As major titles migrate to Blackberry 10, users will follow. Service revenue is expected to decline when carriers negotiate the enterprise fees paid. Blackberry may be able to make up for this with higher unit sales for Blackberry 10. Bearish Case Last Friday, Blackberry was launched on AT&T (T), but there were few line-ups. Sales could be made up mostly by online orders, but it does suggest that marketing by Blackberry is not aggressive enough. Availability for the Nexus 4 at US $299 could weaken user-adoption for Blackberry 10. Samsung’s Galaxy S4 was impressive, spec-wise, but its operating system is quite bloated. Users may care about the hardware, choosing Samsung instead. The new HTC One received positive reviews and consumer interest. Charting Volatility in Blackberry shares may be similar to that of Nokia. The rally in Nokia faded following a strong quarter. Nokia may be releasing Windows Phone Lumia 928 as early as April on the Verizon network. The premium device is reportedly lighter and thinner. It will also have an OLED display, as opposed to an IPS one used on the 920 model.