(February 22, 2021, 1:44 PM EST) -- SPRINGFIELD, Mass. — An investor filed a securities class action lawsuit in Massachusetts federal court on Feb. 16 against a registered securities broker, alleging that the defendant violated federal securities law by holding himself out as an amateur investor when he urged other investors to purchase shares of GameStop Corp. stock to drive up the company’s share price, causing losses to both short sellers and investors who purchased GameStop stock at artificially inflated prices....