Dec. 12 (Bloomberg) -- JPMorgan Chase & Co. was pressed by U.S. regulators to strengthen investor disclosures on proprietary trading almost a year before a wrong-way bet on credit derivatives cost the bank at least $6.2 billion. The Securities and Exchange Commission asked Chief Financial Officer Douglas Braunstein to provide information about the bank’s so-called principal transactions revenue and proprietary trading, according to letters between the agency and the company from June 15 of last year through Feb.