Stocks slumped on Black Friday, extending the week's declines in the abbreviated post-Thanksgiving session. Both the Dow Jones Industrial Average (DJINDICES:^DJI) and the S&P 500 (SNPINDEX:^GSPC) lost about 0.7%.

Today's stock market

Index Percentage Change Point Change
Dow (0.73%) (178.74)
S&P 500 (0.66%) (17.37)

Data source: Yahoo! Finance.

Oil stocks led the broader market lower along with crude oil prices -- with the SPDR S&P Oil & Gas Exploration & Production ETF (NYSEMKT:XOP) falling 3.6% -- despite signals from some OPEC countries of plans for another coordinated supply cut in the coming weeks. Elsewhere, retail stocks helped stem the indexes' losses, with the SPDR S&P Retail ETF (NYSEMKT:XRT) gaining 0.3%.

As for individual stocks, Chinese e-commerce leader JD.com (NASDAQ:JD) and stateside industry juggernaut Amazon.com (NASDAQ:AMZN) both fell. Read on to learn why. 

Asian stock market data on an LED display

Image source: Getty Images.

JD.com investors' worries are twofold

Shares of JD.com lost 5.3% -- making it the worst-performing stock listed on the Nasdaq -- driven by a combination of ongoing trade-war concerns between China and the U.S., as well as an update on the investigation of a rape allegation against its founding CEO, Richard Liu.

On the former, it certainly didn't help that Chinese stocks as a whole plunged on investor jitters ahead of a bilateral trade meeting at the G20 event next week between U.S. President Donald Trump and Chinese President Xi Jingping.

On the latter, Reuters revealed in an exclusive report late Wednesday that U.S. prosecutors are still grappling with evidence in an attempt to decide whether to push forward in the case against Liu concerning an incident that occurred in late August.

"Local prosecutors are weighing evidence that would move the case beyond a 'he said, she said' stalemate," according to Reuters' report. "Among the issues being considered by the Hennepin County Attorney's office: the divergent accounts of what happened that night, the initial determination by police that there was no crime, and the woman's early hesitance to press charges against Liu, Reuters has learned."

It's hardly surprising to see JD stock extending its recent decline as the market assumes a worst-case scenario for both situations.

Amazon brings Black Friday overseas

Meanwhile, shares of Amazon rose as much as 1.3% early in the session after the company reported "record levels" of shopping in the U.K., with over 100,000 toys and 60,000 beauty items purchased from the company's U.K. sites between midnight and midmorning.

This wouldn't be unusual for Amazon if it were talking about its core U.S. business, where the day after Thanksgiving is the busiest retail shopping day of the year and typically marks the start of the important holiday-shopping season. But for many shareholders, Amazon's relative strength in the U.K. today signals the early acceptance of "Black Friday" retail events in any number of potentially lucrative international markets.

But wasn't all smooth sailing. Amazon stock gave up its early gains to close down 1% following separate reports that thousands of union workers across Europe are striking to protest "inhuman conditions" at its warehouses.

John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. Steve Symington has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Amazon and JD.com. The Motley Fool has a disclosure policy.