During the last decade, mortgage originators have been taken on a roller-coaster ride. Prior to the crisis, they couldn't underwrite enough mortgages and, in many cases, went too far by handing out home loans to people who had no hopes of paying them back.

This came to a screeching halt when the credit markets froze in 2008-2009, and origination volumes plummeted. And while the overall market has since been on an uneven path to recovery, it will be years, if not decades, before we see volumes akin to the frenzy between 2003 and 2005.

Out of all of this turmoil, one clear winner has emerged: Wells Fargo. To be fair, the California-based bank has always been a leader in the mortgage market. But it's never dominated the field like it does today.

It's estimated that Wells Fargo underwrites roughly one out of every three domestic mortgages. And up until the middle of last year, it consistently originated more than $100 billion in home loans each quarter. It's a veritable giant, even when compared to the four other biggest mortgage originators in America.

The secret to Wells Fargo's success has been twofold. First, by avoiding the costly mistakes of its competitors -- namely, Bank of America and Citigroup -- it wasn't forced to retreat from the market in order to resize its operations. In the last five years, for instance, Bank of America went from being the nation's biggest originator to being less than a quarter of Wells Fargo's size.

In the second case, Wells Fargo capitalized on its strength going into the crisis by acquiring its larger competitor Wachovia. The move more than doubled the size of Wells Fargo's balance sheet, and gave it a nationwide chain of retail banks through which it could reach prospective homebuyers.

But even Wells Fargo's dominance couldn't shield it from the carnage inflicted on the industry by last year's sharp rise in interest rates following the Federal Reserve's announcement that it would begin reducing its support for the economy.

In the most recent quarter, Wells Fargo originated $47 billion in home loans. That's almost 60% less than the $112 billion that it underwrote in the same period last year. And the same story has unfolded at JPMorgan ChaseUS Bancorp, Bank of America, and Quicken Loans, which saw volumes drop by 44%, 34%, 56%, and 45%, respectively.

At the end of the day, there's no question that the mortgage and housing markets are critical underpinnings of the U.S. economy. And it's for this reason that investors and citizens alike should care deeply about the vitality of the nation's biggest mortgage originators.

Will things pick back up as interest rates continue to normalize? That remains to be seen; but it's certainly worth hoping that will soon be the case.