There should always be a safety net in place for the nation's biggest banks, including JPMorgan Chase, Bank of America, Wells Fargo, and Citigroup. Image credit: iStock/Thinkstock.

Some banks are too big to fail, whether we like it or not. We learned this in the Great Depression, when bank failures transformed an otherwise ordinary recession into a decade-long economic cataclysm that didn't end until World War II.

This lesson still holds true today, as evidenced by the government's 2008 bailouts of Citigroup (C 0.26%) and Bank of America (BAC 1.53%), and to a much lessor extent JPMorgan Chase (JPM 0.65%) and Wells Fargo (WFC 2.73%), among others. Citigroup and Bank of America alone received more than $3.8 trillion worth of assistance, split between capital injections from the U.S. Treasury Department and loans from the Federal Reserve.

Bank

Total Assistance from the Federal Reserve*

Citigroup

$2.5 trillion

Morgan Stanley (MS 0.20%)

$2.0 trillion

Bank of America

$1.3 trillion

Goldman Sachs (GS -0.20%)

$814 billion

JPMorgan Chase

$391 billion

Wells Fargo

$159 billion

These figures exclude capital injections under TARP, which were received by Citigroup, Morgan Stanley, Bank of America, Goldman Sachs, JPMorgan Chase, and Wells Fargo, among others. Source: Government Accountability Office's analysis of Federal Reserve System data, page 131.

Post-crisis regulations have ostensibly eliminated the concept of too big to fail by requiring the nation's biggest banks to submit to annual stress tests and prepare contingency plans in the event that they once again find themselves on the brink of insolvency. Eight banks bear the brunt of the new rules in particular, including JPMorgan Chase, Bank of America, Citigroup, and Wells Fargo. To see the four other firms that make the list, and to learn what makes a bank too big to fail in the first place, simply scroll through the brief slideshow below.

Data from the fourth quarter earnings releases of JPMorgan Chase, Bank of America, Wells Fargo, Citigroup, Goldman Sachs, Morgan Stanley, The Bank of New York Mellon, and State Street. Images in slideshow from Thinkstock.