Lululemon Athletica said on Thursday that economic uncertainty was dampening demand for its pricey athleisure apparel and U.S. tariffs on imports from China and Mexico had squeezed its forecast for the year.

Lululemon stock fell 15% in afternoon trading after CEO Calvin McDonald said consumers are beginning to spend less in response to increased fears about the US economy.

Lululemon reported a strong fourth quarter where revenue increased 13%. But the popular active-wear retailer had a modest outlook for this year based on uncertainty about tariffs and lower consumer spending. Its stock dropped on the lower-than-expected guidance.