Mortgage originations plummeted at all but one of the nation's four biggest banks in 2013. The lone exception? Believe it or not, it was Bank of America (BAC -0.38%), which recently said that its mortgage volume increased 12.9% over the previous year.

At first glance, you'd be excused for concluding this is nothing to write home about. After all, the $89 billion in home loans underwritten by Bank of America in 2013 pales in comparison to former years. In 2009 and 2010, for instance, it originated a total of $677 billion worth of mortgages. That averages out to $338.5 billion a year, or nearly four times its figure from 2013.

On top of this, Bank of America's performance in the mortgage market is a shadow of that reported by its closest competitors Wells Fargo (WFC -0.05%) and JPMorgan Chase (JPM 1.11%). The former had $524 billion in originations last year while the latter's came in at $181 billion.

But comparing Bank of America's 2013 figures to its past or to those of its competitors misses the point. That is, the Charlotte-based bank was the only one of the four largest lenders to actually see mortgage volumes improve on an annual basis last year. The nation's largest mortgage originator Wells Fargo experienced a 33% drop, followed by JPMorgan Chase's 8.5% decline, and Citigroup reported a 0.9% fall.

This notably comes on the heels of Bank of America's highly publicized decision to abandon both its wholesale and correspondent mortgage lending channels in the wake of the financial crisis . Suffice it to say, the strategic choice largely explains why the bank underwrote $378 billion in home loans in 2009 and only $79 billion the year before last.

More recently, however, the nation's second largest bank by assets has delved back into the market anew -- though, this time it's hanging its hat on in-house retail originations. Chief executive officer Brian Moynihan announced the move at an industry conference in December of 2012.

So if you think about a go-forward mortgage business, it will be a servicing portfolio of 6 million loans or so. It will have production of -- right now, we're around about $80 billion, $85 billion, $90 billion a year. We'll probably -- that'll keep going up to $100-some billion.

With a full year under its belt, in turn, this reversal seems to be working. And, to emphasize the point, it's working at a time when originations at most other banks are dropping due to the uptick in mortgage rates.

Is this a sign of things to come for Bank of America? It's obviously too early to say. At the same time, however, there's simply no question that this is an extremely positive development for both the bank and its shareholders.