Research In Motion released quarterly revenue estimates that were below expectations, lowered its earnings forecast, and announced it would be cutting jobs on Thursday, leading to a stock nosedive. The BlackBerry producer's shares tumbled to below US$28 on Friday -- the lowest level in nearly five years. Some of the company's major stockholders are jumping ship. One of its largest investors, Jarislowsky Fraser, cut its stake in half. RIM, which has been losing out to Android-powered phones and Apple's iPhone, has not had a major handset release since last August.