Despite the government saying taxpayers should never again have to rescue a failing bank, an article in Bloomberg says many investors still believe mega banks would receive lifelines in times of distress.

Several big banks have benefited from tax breaks and Federal Reserve largesse since the end of 2008 in the form of additional income from the central bank's mortgage-bond purchases and the interest it pays for banks deposits, the article explains. 

"The big banks have the taxpayers standing behind them, so people who lend them money know they’ll be paid back," says Cornelius Hurley, director of the Center for Finance Law & Policy at Boston University and former assistant general counsel at the Fed. "That too big to fail no longer exists is not credible."