JPMorgan Chase CEO Jamie Dimon was back for round two on Tuesday, defending his company's $2 billion trading loss before Congress. The House Committee on Financial Services has been tough on Dimon this week. “Is gambling investing?” Rep. Gary Ackerman asked Dimon. "We don’t gamble. We do make mistakes,” Dimon replied. Dimon also said he was "dead wrong" when he dismissed reports about trading losses as a "tempest in a teapot." The executive was less humble when it came to his opinion of global economic regulation. "To a hammer, everything is a nail," Dimon said. "You guys can do what you want."