Kohl’s (KSS), the mid-tier department store trying to return to its glory days, gets to keep bragging that its quarterly comparable sales growth streak continues unbroken. But only barely.

The retailer said on Thursday that comparable sales (online business and sales at stores open at least a year) rose a paltry 0.4% in the holiday quarter, the fifth straight period of growth and one that suggests that Kohl’s strategy is at least sparing the company from the kinds of declines buffeting fellow department store Macy’s (M). That company reported a 5.2% decline in comparable sales for November and December. (Full quarterly results will come later this month.)

But for a company with a goal to add $2 billion to its 2014 annual sales by next year and hit $21 billion, the anemic pace has to be a disappointment: of those five quarters, growth only exceeded 1.5% once. For the fiscal year just ended, comparable sales were up 0.7%, hardly a performance that will reassure anyone that Kohl’s knows how to reinvent itself in a tough era for department stores. Shares were down 15% by late morning, suggesting investors are losing faith.

In 2014, Kohl’s launched its “Greatness Agenda,” which focused its turnaround efforts on improving its in-house brands (it is about to relaunch its billion-dollar Sonoma denim brand), ramping up its digital efforts, and trying out new formats, like a chain of much smaller stores that is in the works.

Kohl’s CEO Kevin Mansell blamed a choppy retail environment and, like many other retailers, the weather for sales that came in below its expectations.

“Sales were very volatile and less than planned in the fourth quarter,” he said. Though sales were good in the peak Black Friday-to-Christmas season, he added, business was weak at other points in the quarter. In particular, a warm January hit demand for cold-weather items, a plausible excuse for a national retailer that nonetheless skews heavily to the Midwest and Eastern half of the U.S.

One thing he didn’t mention that could also be hurting Kohl’s: J.C. Penney’s (JCP) improving business. That department store reported best-in-class holiday season sales growth.

On the bright side, Kohl’s heavy investments in e-commerce and integrating its stores with its digital business seem to paying off, with online sales rising 30% during the quarter. Still, the sales shortfall led Kohl’s to slash its profit forecast for the quarter to $3.95-$4.00 from $4.40 to $4.60 per share.

Last month, the Wall Street Journal reported that Kohl’s may hire an investment bank to advise it on various alternatives, including taking itself private, to combat any incursion by such investors, worried that the company’s big stock swoon in the past year could attract unwanted attention.

One thing is for sure: 0.4% sales growth for the holiday quarter is not the kind of performance that will mollify restless investors.