Wells Fargo, Chase and Bank of America became larger during the financial crisis as they acquired other major banks that had fallen or were about to fall. This Wall Street Journal article
reviews problems that can occur when "Market power is concentrating in the hands of the nation's largest banks." Savers and those looking for loans without the best credit are hurt the most:
The giant banks are gambling that their vast array of products and convenient locations are enough to keep a grip on most customers no matter how low deposit rates sink.
Make sure you don't settle for low deposit rates at any of the mega-banks. And don't forget that credit unions can be more convenient than you might think (see thread