What: Clothing retailer Under Armour's (NYSE:UAA) stock rose by 19% during the month of July, according to S&P Capital IQ data. The bounce pushed shares to a new all-time high and investors are now sitting on a 46% gain, year to date.

UA Chart

UA data by YCharts.

So what: The stock popped in response to second-quarter earnings results, released on July 23, which beat Wall Street forecasts on both the top and bottom lines. Under Armour posted 29% higher sales for the period, which was powered by broad gains across regional markets and product lines. 

Ua Backback

Backpack sales helped UA's accessories business spike higher 40% last quarter. Source: Under Armour.

Apparel sales improved by 29% thanks to success with the training and base layer clothing brands. Footwear sales spiked higher by 40% as the Stephen Curry shoe line proved popular. And Under Armour even managed to push into new categories, expanding its accessories sales on bag and backpack product introductions.

At the same time, the business showed promise from two sales channels that will likely drive sustainably higher profit and sales gains. International revenue almost doubled and is now responsible for over 10% of sales. That gain suggests Under Armour could quickly grow its overseas business toward the 54% of sales that global competitor Nike enjoys. Under Armour's e-commerce sales also improved faster than the overall business, jumping 33%. 

There were some weak points in this earnings announcement, though. Profitability fell by a percentage point to 48% of sales and expenses rose as Under Armour ramped up investments in new product launches. These negative trends pushed operating income lower despite the sales jump: Under Armour earned $32 million of profit compared to $35 million in the prior-year period.

Now what: Still, management is confident that the business can post accelerating growth through the second half of the year. Executives boosted their 2015 sales outlook to $3.84 billion, or 25% above last year's result.

They also raised their profit forecast. CEO Kevin Plank and his team think operating earnings will be as much as $408 million this year, or 15% above 2014's figure. "This year has highlighted that the right investments are key to not only driving near-term results, but building the foundation for the unlimited potential of the Under Armour Brand," Plank said.

Demitrios Kalogeropoulos owns shares of Apple and Nike. The Motley Fool recommends Nike. It recommends and owns shares of Apple and Under Armour. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.