In 2012, Texas had a Gross Domestic Product, which measures its total economic output, of $1.4 trillion dollars -- which would make it the 12th largest country in the world by GDP according to The World Bank, eclipsing Spain, Mexico, and South Korea. Knowing that, it is understandable that many banks would vie for the honor of being called the top bank in Texas.

Yet the banks at the top of the list may surprise you -- and one of them is actually adding to its share of the market in the Lone Star State at an unmatched rate.

As of this June, the top banks by deposits in Texas were as follows:

Source: FDIC.

While the deposit data can be incredibly useful in the instances of USAA Federal Savings Bank and Wells Fargo Bank South Central, banks often have holding companies located in specific states because of favorable regulation. Its presence in the state does not necessarily indicate that all of those deposits are from customers located in Texas -- so for the purposes of this analysis, those banks will be excluded.

One of the helpful things to gauge is the market share -- and while BBVA Compass and Frost Bank have seen relatively stable market share around 5% and 3% -- you'll see that one of the top three banks is adding to its market share in a big way:

Source: FDIC.

As you can see in the chart above, Bank of America had a clear lead over Wells Fargo in 2010 and was less than 2% away from JPMorgan Chase -- but things have changed dramatically since then, as the gap between first and second now stands at almost 7%.

Since 2010, JPMorgan has watched its total deposits grow by 56% in Texas, whereas Bank of America and Wells Fargo have seen theirs grow by 15% and 27%, respectively. Meanwhile the total deposits in Texas has grown by 30%.

While the expansions of banks into foreign countries is often explored in depth -- rarely do we pay enough attention to those banks that aggressively pursue growth in specific states, especially those as large as Texas. In addition, Texas has also seen its own GDP grow by 14% from 2010-2012, while the U.S. has watched its GDP only grow by 9%. So JPMorgan gaining market share in a big way in this big state is undoubtedly a good thing.

Fool contributor Patrick Morris owns shares of Bank of America. The Motley Fool recommends Bank of America and Wells Fargo. The Motley Fool owns shares of Bank of America, JPMorgan Chase, and Wells Fargo. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.