What happened Shares of Office Depot Inc (NASDAQ: ODP) were tumbling today after the struggling office supply retailer was downgraded by J.P. Morgan. As of 11:27 a.m. EDT, the stock was down 13.3%. Analyst Chris Horvers lowered his rating on Office Depot to underweight from neutral, explaining that the office supply category is shrinking, and that the company is losing business-to-business market share as it faces increasing competition from Staples as it goes private and Amazon.com, which recently launched a Prime service for businesses. Image source: Getty Images. So what The office supply retailer is well aware of the headwinds it's facing. Three years ago, it merged with Office Max and in 2015 sought a merger with Staples, which was blocked at various junctures by regulators. Staples instead agreed to sell itself to private equity firm Sycamore Partners, evidence that it also faced a bleak future as a public company, and Office Depot said early this month it would acquire IT services provider Compucom for $1 billion. Shares sold off on that announcement, however, as Office Depot also lowered its guidance in the same press release. Now what Office Depot approached a 52-week low following today's downgrade, though Horvers' note says nothing new about the retailer's predicament. Despite its troubles, the office supply retailer is still profitable, and the Compucom deal has the potential to shore up its business. The retailer's shares are also cheap at a P/E of just 7, but the challenges it faces justify such a valuation. Expect continued volatility as the company absorbs Compucom and tries to stabilize its business. The next date for investors to watch is Thursday, November 9, when the retailer reports third-quarter earnings before the market opens. 10 stocks we like better than Office DepotWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the 10 best stocks for investors to buy right now... and Office Depot wasn't one of them! That's right -- they think these 10 stocks are even better buys. Click here to learn about these picks! *Stock Advisor returns as of October 9, 2017John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. Jeremy Bowman has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Amazon. The Motley Fool has a disclosure policy.