Quicken Loans Inc. CEO Bill Emerson went from a walk-on with Penn State University's football team to part of coach Joe Paterno's 1982 championship squad, and then a captain two years later.
Mr. Emerson last year led Quicken, the mortgage lender owned by billionaire Dan Gilbert that was the 34th largest in 2006 as the U.S. housing boom ended, to near the very top of an industry that's reaping the rewards of a refinancing boom.
The Detroit-based company overtook Citigroup Inc. as the fifth-ranked originator in the third quarter, and then surpassed U.S. Bancorp and Bank of America Corp. After its lending jumped to $70 billion in 2012 from a previous record of $30 billion, it still has room to grow, according to Mr. Emerson.
"Our mission is to do as much or more than we did last year," Mr. Emerson, 50, said in an interview at Bloomberg News headquarters in New York. "There's a massive market out there, and 93 out of 100 people still wake up and go somewhere else."
The firm's rapid expansion reflects its opportunities and ambitions, with its staff growing to about 8,900 this month from 5,400 a year ago. About 7,000 are in Detroit, where founder and chairman Mr. Gilbert -- also the majority owner of investment firm Rock Ventures LLC and the Cleveland Cavaliers basketball team -- moved the lender in 2010 and bought other properties in a long-term bet on that city's revitalization.
The company is among firms reshaping a mortgage industry broken by the housing bust that drove values down by 35 percent across the country before a recovery that began last year.
For surviving lenders, business has been booming, with new loans rising 22 percent in 2012 to $1.8 trillion as the Fed drove 30-year mortgage rates to record lows below 3.4 percent and President Barack Obama expanded federal refinancing programs. Quicken joined lenders including U.S. Bancorp, Flagstar Bancorp Inc., Everbank Financial Corp. and PennyMac Mortgage Investment Trust in growing even faster.
Retreats by large lenders such as Bank of America left a "tremendous amount of market share available," said John Robbins, the head of Bexil American Mortgage Inc., who founded two mortgage firms sold to banks that are now part of Wells Fargo & Co. and JPMorgan Chase & Co.
Quicken made about $25 billion of mortgages last quarter, exceeding the $22.1 billion of mortgage production reported by U.S. Bancorp. Bank of America, the second-largest U.S. bank by assets, said it funded $22.5 billion in residential mortgages and home-equity loans as it seeks to rebuild in the business, while Citigroup reported $16.8 billion in mortgage originations.
Those 2012 volumes would have earned Quicken more than $1 billion in profit, based on mortgage earnings data reported by Wells Fargo, the market leader with $524 billion of originations last year.
Quicken has been profitable every year, Mr. Emerson said, declining to provide figures. It has "no near-term game plan in terms of an exit strategy" such as a sale or initial public offering, he said.
Quicken's centralized operations make use of proprietary software designed to make it more customer-friendly and efficient, such as by breaking up work typically done by one processor into 16 different jobs, he said.
That "fantastic technology" has created a "very scalable model," said James Raezer, head of mortgage finance in the Americas at Royal Bank of Scotland Group Plc's securities arm, one of its lenders.
Mr. Emerson has seen his own stature in the industry rise, with roles at the Mortgage Bankers Association and Housing Policy Council, an affiliate of the Financial Services Roundtable led by the industry's top CEOs.
Still, his biggest challenges may be ahead.
Refinancing, which accounted for 71 percent of originations last year, may fall to 58 percent of volumes this year and 34 percent in 2014, as rates increase. That's going to help bring down total lending by 39 percent to $1.1 trillion, according to a Mortgage Bankers Association forecast. Economists predict that 10-year Treasury yields, which help guide borrowing costs, will rise.