Investing.com -- Under Armour (NYSE: UAA) shares plunged premarket on Tuesday after the company reported fourth-quarter results that missed analyst expectations and provided a cautious outlook for fiscal 2027.

Shares are down around 12.7% premarket following the announcement.

The athletic apparel company posted an adjusted loss per share of -$0.03 for the fourth quarter, missing the analyst estimate of -$0.02. Revenue declined 1% to $1.2 billion, though this exceeded the consensus estimate of $1.17 billion.

Compared to the same quarter last year, revenue decreased 1%, or 4% on a constant currency basis. The company attributed the revenue decline to a 7% drop in North America sales to $641 million, partially offset by 10% growth in international revenue to $539 million.

Gross margin declined 360 basis points on an adjusted basis to 43.1%, primarily due to higher tariffs, increased product costs, pricing headwinds, and unfavorable regional mix.

For fiscal 2027, Under Armour expects revenue to decline slightly YoY, with adjusted diluted earnings per share ranging from $0.08 to $0.12. The midpoint of $0.10 reflects continued external cost pressures despite expected tariff-related refunds.

"Our fiscal 2026 performance reflects the ongoing intentional steps we're taking to reset the business and restore the discipline required to operate as a best-in-class brand," said Kevin Plank, President and CEO of Under Armour. "As our topline stabilizes in fiscal 2027, we are applying the same rigor that is strengthening our product engine to our storytelling capabilities."

For the full fiscal year 2026, Under Armour reported revenue of $5.0 billion, down 4% YoY, with an adjusted diluted earnings per share of $0.12. The company recorded a net loss of $496 million, which included a $247 million valuation allowance on U.S. federal deferred tax assets.