Some research topics in banking and finance include investment bubbles, banking history, measuring personal wealth, annuity markets, banks and risk securities, and bank capital.
Some specific subtopics within these topics include: past and present investment bubbles, bank panics, the statistical reliability of surveys to measure personal wealth, the health of the annuity market in relation to the health of the insurance market, justifiability of bank returns coming from risk investments, and regulation of bank capital.
For example, you might research historical investment bubbles, such as the dotcom bubble of 2000, the housing bubble of 2008 or the current stock market bubble predicted by presidential hopeful Donald Trump and Trump's possible future Secretary of the Treasury, Carl Icahn. Granted, the predicted present stock market bubble would be more challenging to research, but the dotcom and housing bubbles could add background and comparative contrasts, thereby expanding your field of research.
As another example illustrating the suggestions above, under the topic of bank history, you might explore the history of the bank panic of 2007. A good title for beginning your research on the 2007 panic is Slapped by the Invisible Hand: The Panic of 2007, written by Gary B. Gorton. Gorton examines and seeks an explanation for the 2007 bank panic while putting it in perspective with earlier bank panics.
An example of a contemporary banking subtopic would be the new regulations on bank capital requirements proposed in 2013 by the "Federal Deposit Insurance Corporation, along with the Federal Reserve and the Office of the Comptroller of the Currency," as explained by the New York Times. This increase in bank capital (the equity funding financial transactions and the reserves keeping the bank solvent in the event of losses, such as housing derivative losses) would make banks' financial transactions more "expensive" for the bank because they could lend/invest less of their capital; they would conversely have to reserve more of their capital, leaving it idle.
To generate more topic and subtopic ideas for research on banking and finance, Questia.com has a topic-generating program that links topics to subtopics that link to appropriate titles for the subtopics. This topic-generating program provides a wealth of ideas. More topics are discussed in Emerging Topics in Banking and Finance, a collection of international expert commentaries edited by Emma J. Fuchs and Finn Braun, for example, the topic of "the cloudy performance of Chinese Banks."