US big banks just keep getting bigger. Accoring to a report by SNL Financial, the five largest US lenders control 44.2% of the industry's assets. This is up from 43.5% in 2012 and 38.4 in 2007, before the economic crisis.

According to Wall Street Journal, an easing of regulatory strictures that accelerated in the 1990s has encouraged big banks to consolidate. The trend was further cemented during the 2008 financial crisis when the government pushed stronger banks like JPMorgan Chase & Co. and Wells Fargo & Co. to buy weaker competitors.

There were 6,891 banks as of the third quarter, down from a peak of 18,000. Between 1984 and 2011, more than 10,000 banks disappeared through mergers or failures, based on data from the Federal Deposit Insurance Corporation (FDIC).

The banking units of JPMorgan Chase, Bank of America Corp., Citigroup Inc., Wells Fargo and US Bancorp (USB) held $6.46 trillion in assets as of the third quarter, the SNL report said. The total for the rest of the banking industry, comprised of thousands of midsized, regional and smaller players, was $8.15 trillion, the report said.