(January 13, 2016, 10:48 AM EST) -- SAN FRANCISCO — A shareholder filed a securities class action lawsuit against a fitness-tracking device manufacturer and certain of its executive officers in California federal court on Jan. 11, alleging that the defendants issued a series of misrepresentations that caused the company’s stock to trade at an artificially high rate in violation of federal securities laws (Brian H. Robb v. Fitbit Inc., et al., No. 16-151, N.D. Calif.)....