Numbers will lie to you, if you let them. You can't always rely upon rote statistical analysis to steer you toward the best ideas (and/or away from trouble). That brings me to small-cap L.A.-based WilshireBancorp (NASDAQ:WIBC). While this bank has some truly excellent-looking operational statistics, the total growth-and-value package isn't quite as appealing to me.

Wilshire is one of the four big California banks that focuses extensively on Korean-American customers. It shares that niche with Nara Bancorp (NASDAQ:NARA), HanmiFinancial (NASDAQ:HAFC), and CenterFinancial (NASDAQ:CLFC), but also competes with larger banks like Bank ofAmerica (NYSE:BAC), Wells Fargo (NYSE:WFC), and Washington Mutual (NYSE:WM).

As I just said, many of the numbers look very good here. Net income was up 29%, book value was up 26%, and both return on assets and equity were strong at 1.84% and 26.4% respectively. Top that off with a nearly unheard-of efficiency ratio of 38.5, and everything should be great, right?

Eh, I'm not so sure.

See, while net interest income was up 27%, net interest margin was hurt by fast-rising interest expense. And while I didn't see the company provide a calculation for cost of funds, my rough math suggests that it was greater than 3.4% or so. Likewise, loan growth was a strong-looking 23.5%, but it seems like the company is making more hybrid fixed/variable loans that actually yield less than older loans on the balance sheet.

If I'm right about that (and these are estimates), then the company is paying more for deposits and getting less on its loans. That's not good. It also raises the risk that Wilshire will prove vulnerable to "hot money" customers that aren't loyal to the bank, but rather to the interest on their accounts. What's more, this bank gets around 20% of its pre-tax income from gains on loan sales, which is often seen as a lower-quality source of income.

When I value this stock on an economic-value-created basis, I come away thinking that it's no bargain at today's prices. If my estimates on funding costs and loan yields are right, it might have a much harder time producing the sort of growth to which investors have become accustomed. All in all, then, this bank gets little love from me today.

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Fool contributor Stephen Simpson has no financial interest in any stocks mentioned (that means he's neither long nor short the shares).