Merrill Lynch, Pierce, Fenner & Smith (Merrill Lynch) (plaintiff) sued Gargallo (defendant) in Ohio state court for collection of debt due for losses incurred by Gargallo in a margin brokerage account he opened with Merrill Lynch. Gargallo counterclaimed, alleging Merrill Lynch had caused his losses through negligence and misrepresentation and had violated federal securities law. The court dismissed Gargallo’s counterclaims with prejudice for failing to comply with Merrill Lynch’s discovery requests. Gargallo then filed a complaint in United States District Court for the Southern District of Ohio, re-alleging the violations of federal securities law which was dismissed on res judicata grounds. Gargallo appealed the dismissal of his suit.