What happened

Shares of Under Armour Inc. (NYSE:UA)(NYSE:UAA) declined 19.3% in August, according to data from S&P Global Market Intelligence, following not only a series of disappointing earnings reports from its retail partners, but also critical words from a rival sponsored athlete.

More specifically on the former, last month investors endured terrible earnings reports from Foot Locker, The Finish Line, and Dick's Sporting Goods, signaling deeper pain in the retail industry on which performance apparel and athletic footwear companies like Under Armour rely.

Stephen Curry holding one of his signature Under Armour shoes

IMAGE SOURCE: UNDER ARMOUR

So what

It also didn't help that Under Armour shares were already reeling from a slowdown in its core North American apparel market, which was spurred in part by multiple sporting goods retailer bankruptcies over the past year. As a result, Under Armour most recently implemented a restructuring last quarter with the goals of streamlining operations, reducing costs, and more effectively allocating its cash to maximize returns on investment.

If that wasn't enough, NBA Finals MVP (and Nike-sponsored athlete) Kevin Durant insisted later in the month during a radio interview that "nobody wants to play in Under Armours." Shares of Under Armour dropped nearly 3% the following day as a result.

To be fair, Durant's teammate Stephen Curry -- who is arguably Under Armour's highest-profile athlete and owns an equity stake in the business -- responded earlier this week by insisting his comments don't "ring true at all."

Curry elaborated:

I told him that he has a certain opinion based on his experience growing up in the Nike business. Where we were four years ago, and where we are now -- you can't tell me nobody wants to wear our shoes. I know for a fact that they do.

Now what

Of course, that still leaves the question of whether Under Armour is sharing the pain its retail partners are so obviously feeling right now. But investors will likely need to wait until the its third-quarter report in early November for more color on the answer to that question.

For now, while I've already argued that Under Armour is a compelling buy after the recent drop, it was no surprise to see the stock pulling back hard after its travails last month.

Steve Symington owns shares of Under Armour (C Shares). The Motley Fool owns shares of and recommends Under Armour (A Shares) and Under Armour (C Shares). The Motley Fool has a disclosure policy.