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What: Shares of Walker & Dunlop (NYSE:WD) were tumbling today, down as much as 20% after it lowered its loan origination guidance for the current quarter.

So what: The commercial real estate lender dropped its loan origination forecast to $1.7-$1.9 billion from a previous range of $2.0-$2.5 billion, blaming rising interest rates and caps on loans that Fannie Mae and Freddie Mac can hold. Walker & Dunlop sells about half of its loans to Fannie & Freddie. Year-to-date loan originations are still projected to be up 43-48% from a year ago, however. Separately, the company also entered into a $150-$200 million term loan today.

Now what: Today's drop was the second such decline for Walker & Dunlop in just two months; shares dropped 15% on August 8 after the company delivered a disappointing earnings report. In fact, Walker & Dunlop has badly missed earnings estimates in its last three quarters, generally a red flag for stocks. Shares are down 40% in that time, and show no sign of rebounding after today's update. The stock may seem cheap at a P/E around 8, but I'd like to see conditions improve before getting on board.

Fool contributor Jeremy Bowman has no position in any stocks mentioned. The Motley Fool owns shares of Walker & Dunlop. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.