NEW YORK (TheStreet) -- BlackBerry was a big loser before market open, tumbling 3.88% to $15.85. Shares of the embattled Canadian handset maker, which recently unveiled its much-delayed BlackBerry 10 technology, have been under pressure recently. The company's stock lost 2.77% during Friday's trading. BlackBerry was also the most active premarket Nasdaq stock on Monday on share volume of 763,942. ... Click to view a price quote on BBRY. Click to research the Telecommunications industry.