Eight of the largest U.S. banks will need fatter capital cushions as part of U.S. regulators’ latest efforts to make the financial system less risky, the Wall Street Journal reported today. The biggest impact will be felt by JPMorgan Chase & Co., the nation’s largest bank by assets, which is $21 billion short of the requirement, according to Fed officials. Fed Vice Chairman Stanley Fischer — in an apparent misstep — disclosed during an open meeting that J.P. Morgan is the only one of the eight banks to face a shortfall under the proposed rule. Fed staff had closely guarded details of the proposal’s impact on specific firms. The proposal, which will be phased in starting in 2016 and take full effect in 2019, is aimed squarely at pushing big banks to shrink, an outcome regulators were explicit in saying they hope to encourage to reduce the likelihood a firm’s failure could require bailouts or damage the broader economy.