United Wholesale Mortgage kicked off 2024 as the number one lender in the U.S. in overall and wholesale production as well as purchase mortgage originations, but it has not been all smooth sailing.

The company's fourth quarter purchase production of $20.68 billion topped Rocket's total fourth quarter closed loan volume of $17.26 billion, though its total volume of $24.4 billion for the period was lower than $29.7 billion UWM reported in the third quarter and $25.1 billion during the fourth quarter of 2022.

For the full year, UWM lost on a GAAP basis $69.8 million in 2023, as compared with $931.9 million of net income one year prior. The 2023 loss was driven by an $854.1 million mark-to-market value hit to its mortgage servicing rights.

Despite the lender's MSR challenges, Mat Ishbia, UWM's chairman and CEO, is undeterred: "I look at these things as opportunities," he said in the company's earnings call in February.

Read more: UWM loses money in 4Q but remains top lender 

UWM is also facing challenges of another kind. Following a legal dispute over an employment contract the lender's employees were required to sign in recent years, a National Labor Relations Board judge ruled on Jan. 11 that it does in fact violate numerous labor laws.

Administrative Law Judge Susannah Merritt said in her decision that employees would read many of UWM's terms as unlawfully prohibiting them from discussing workplace conditions, disputes, wages, union efforts and more. The judge also found language around arbitration, social media use and media contact in violation of labor laws.

UWM announced in a statement that it disagreed with the judge's findings and planned to appeal, but should the NLRB ruling be confirmed, in addition to rescinding unlawful portions of the contract and distributing a revised version to current and former workers, the company must post a 4-page appendix, digitally and around its office, for a 60-day period which states the NLRB found it in violation of labor law and reasserts workers' rights.

Read more: Cyberattacks, labor disputes among legal battles to watch this year

While waging this and a number of other legal battles on the originations side of the business, UWM has taken a proactive step to help its broker partners get ahead of its rivals in the next wave of refinances by announcing Refi 100, a special 100-basis point pricing promotion for conventional rate-and-term refi rates.

In a November third quarter earnings call, Ishbia said the firm had hired more than 1,000 workers in preparation for a big, or mini, refi boom. Indeed, refis in the week ending Jan. 26 made up 34.2% of total mortgage applications, up from 32.7% the prior week according to the Mortgage Bankers Association's latest survey. In addition, Fannie Mae in January projected 2024 single-family refi volume to shoot up $490 billion from just $246 billion last year.

Catch up on all our recent coverage of the nation's top lender.