When it comes to bank stocks, size does indeed matter.

Not only do the largest regional banks -- including SunTrust Banks (NYSE:STI), BB&T (NYSE:TFC), and Capital One (NYSE:COF) -- benefit from economies of scale, but they're also typically much more diversified than their community banking counterparts. These are two of the reasons that shares of Capital One and BB&T, after adjusting for dividends and buybacks, have outperformed the S&P 500 over the past two decades.

Given this, investors in bank stocks should keep a rough tally of where specific banks fall in the size spectrum. The slideshow below does just that, using data from the third-quarter earnings releases of SunTrust Banks, BB&T, Capital One, and others, to rank the biggest regional banks in the United States by total assets.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.