Hence, it makes the markets nervous when this box of chocolates gets opened. The return of boring banks? Newly proposed capital rules designed to make banks safer, and less likely to need bailouts in time of crisis, are further depressing each of the Big Four's stocks today. Like B of A, Citigroup Inc. (NYSE : C ), Wells Fargo & Co (NYSE : WFC ), and JPMorgan Chase & Co. (NYSE : JPM ) are also trading down. Yesterday the Fed, the Office of the Comptroller of the Currency, and the Federal Deposit Insurance Corporation proposed that banks double the amount of capital they hold "as protection against every loan, investment, building security, and other asset on their books — not just the risky ones," according to today's Wall Street Journal. And the eight biggest bank-holding companies in particular would be required to increase their leverage ratios to 5%. Right now, all global regulators require is a leverage ratio of 3%.