Under Armour's shares skidded about 23 percent Tuesday after the sportswear maker reported lower-than-expected quarterly sales and announced that Chief Financial Officer Chip Molloy will step down.
The stock price was $19.17, down more than 23 percent from Monday's close.
Under Armour said Molloy is leaving for personal reasons. It did not elaborate. Molloy, the former CFO of PetSmart, joined Under Armour on last January.
The company's sales were hurt by intense competition and slowing growth in North America.
The company said net income fell to $104.9 million in the fourth quarter ended Dec. 31 from $105.6 million a year earlier.
On a per-share basis, earnings fell to 23 cents per for Class A, Class B and Class C shares from 24 cents a year earlier.
The company's net revenue rose about 12 percent to $1.31 billion, its slowest sales growth in eight years. Analysts on average expected $1.41 billion, according to Thomson Reuters.
Susan Anderson, a consumer research analyst at FBR Capital Markets, said on CNBC's "Squawk Box" that she was not overly surprised by the performance, given the industry's oversupply and recent bankruptcies like that of Sports Authority last June.
"I think we are, based on their guidance, going to see slower growth over the next year as we ... work through some North America issues," she said, noting several promising areas in the report where Under Armour could see improvement.
"We are still seeing international growth over 50 percent and then also footwear, which I think was expected to be light, was still very strong, over 30 percent," she continued. "So I think those are really the two growth platforms that we're going to start to see take hold over the next several years."
She said Under Armour stock was still worth holding for the long term.
"I like it over Nike," she said. "It's one that is still going to have double-digit top-line growth, which is very hard to find these days ... in retail or apparel."
And, despite Nike's $30.5 billion in revenue for 2016 compared to Under Armour's $4.8 billion, "I think there's still a long runway of growth for them," Anderson said. "I think it's going to come out a winner."
— Reuters contributed to this report.