What happened

Shares of Ellie Mae (NYSE:ELLI) are sinking today, down by about 16% as of 12:30 p.m. EDT, after the company reported second-quarter earnings and reduced guidance.

So what

Ellie Mae has enjoyed unrelenting growth in the years following the financial crisis as banks and other mortgage originators turn to its software packages to help them navigate new mortgage regulations and compliance requirements.

This quarter, Ellie Mae reported that its net income increased 78% compared to the year-ago period. However, much of that increase was driven by tax impacts, rather than operating factors. On a pre-tax basis, income grew just 6.7% in the second quarter compared to the year-ago period.

Paper house cut out with a set of house keys on top

As rates rise, fewer homeowners are refinancing their mortgages. Image source: Getty Images.

Weak growth was the result of lower mortgage refinancing volume and a tight supply of homes for would-be buyers. On the conference call, management noted that the average user closed only 1.35 loans per month during the second quarter, down from 1.51 closed loans per user in the year-ago period.

Now what

Lower refinance mortgage volumes aren't just a first-half story. Ellie Mae CFO Matthew LaVay said that "[i]n the second half of the year, mortgage volume is expected to be down 28% year over year, driven by refinances down 57% year over year" in prepared remarks on the company's conference call.

The company went on to lay out guidance that it would earn adjusted net income of $1.47 to $1.50 per share for the full year, well below the average Wall Street analyst estimate of $1.90 per share.

Jordan Wathen has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Ellie Mae. The Motley Fool has a disclosure policy.