However, Symitar President Ted Bilke countered that as Symitar works through its installation pipeline, it will lead the $1 billion and larger category.

“We see ourselves in the leadership position in cores with credit unions,” he said.

Third party experts have been quick to offer insights into what is occurring in the core system market, especially for larger credit unions.

Brad Smith, president of core consultant Abound Resources in Austin, Texas, attributed the apparent Symitar rise to lingering problems faced by its arch rival, Brookfield, Wis.-based Fiserv. That firm suffered significant embarrassment when it killed off development of its Acumen core, which had been billed as a new core for a new era, but was plagued by problems.

Fiserv also in January 2013 bought for roughly $1 billion competitor Open Solutions and its innovative DNA core, largely to satisfy the large credit unions for which Acumen had been intended.

“Fiserv has been focused on the OSI acquisition/integration and cleaning up the Acumen mess and still doesn't seem to have a good go-to-market strategy for larger credit unions. As they've stumbled, Symitar has been building on its success and still has the momentum,” Smith said.

Atlanta-based consultant David Gibbard, formerly a senior vice president at Birmingham, Ala.-based technology CUSO EPL, said Symitar is ascending because “credit unions feel they have more control over other solutions when they are on Symitar.”

That, he explained, is because Fiserv's reputation is that it prefers to use its own, proprietary solutions for home banking, mobile banking, and the like to augment a core.

Symitar, on the other hand, portrays its core system as open; that is, easy to interface with add-ons. That difference, Gibbard said, is gaining favor with credit union executives.

Sam Kilmer, a senior director at Cornerstone Advisors in Scottsdale, Ariz., said, “Symitar already grabbed the momentum before, and now with their solid client satisfaction, Symitar has just increasingly become the safe option.”

Scott Hodgins, another Cornerstone expert, expressed a similar opinion, but added that all is not gloomy for Fiserv.

“Smaller credit unions buy Symitar for the safe bet; big credit unions because of their integration openness and very strong retail functionality. DNA is being much better received and more widely included in system selections now after the Fiserv acquisition.”

At Symitar, Bilke said when he goes head to head against DNA, “we win 55% of the time.”

He agreed that openness is a Symitar advantage.

“When we win, that's often why,” he said.