Here are five things you must know for Wednesday, Sept. 5:

1. -- Trade Tensions Pull Stocks Lower

U.S. stock futures pointed to losses for Wall Street on Wednesday, Sept. 5, and global stocks were weak for a second consecutive session with investors citing ongoing trade tensions between Washington and its major economic allies as catalysts for the declines.

Renewed turmoil in emerging markets also led to a defensive tone in trading that has lifted the U.S. dollar to the highest level in two weeks.

Contracts tied to the Dow Jones Industrial Average  fell 932 points, futures for the S&P 500  were down 7 points, and Nasdaq futures slid 21.50 points.

Stalled talks between the U.S. and Canada on a overhaul of NAFTA are expected to resume on Wednesday, while the U.S. could impose fresh tariffs on $200 billion worth of China-made goods as soon as Thursday, Sept. 6.

The economic calendar in the U.S. on Wednesday includes International Trade for July at 8:30 a.m. ET.

Earnings reports are expected Wednesday from Vera Bradley Inc. (VRA , Verifone Systems Inc. (PAY , Christopher & Banks Corp. (CBK and Verint Systems Inc. (VRNT .

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2. -- Twitter and Facebook Face a Senate Grilling

Twitter Inc. (TWTR CEO Jack Dorsey and Facebook Inc. (FB Chief Operating Officer Sheryl Sandberg are due to testify on Wednesday before the U.S. Senate Select Committee on Intelligence in an extended grilling that will cover foreign influence operations on U.S. elections.

With the November mid-term elections just two months away, the testimony may shed light on how prepared the companies are to fend off election interference -- and what they've done to combat abuse and fake accounts on their platforms, an issue that kneecapped the social media stocks last quarter, wrote TheStreet's Annie Gaus. Since reporting their earnings in July, Twitter has fallen 18% and Facebook has declined 19%.

Alphabet Inc. (GOOGL  won't be sending its CEO, Larry Page. Page was invited by the committee in July, but Alphabet instead offered its chief legal officer, Kent Walker, an offer that was rejected by the committee.

Facebook and Alphabet are is holdings in Jim Cramer's Action Alerts PLUS member club. Want to be alerted before Jim Cramer buys or sells FB or GOOGL? Learn more now.

3. -- Workday Slumps Despite Beating Estimates

Workday Inc. (WDAY fell 1.7% in premarket trading on Wednesday after posting fairly solid quarterly earnings but Wall Street was left wanting more from the cloud software company.

The company reported fiscal second-quarter revenue of $671.7 million, up 28% from a year earlier, and non-GAAP earnings of 31 cents a share, topping analysts' estimates of $663.1 million and 26 cents. Workday's billings, defined as its revenue plus the sequential change in its unearned revenue balance, rose 35% from a year earlier to $739.8 million, beating consensus.

Workday also said it expects subscription revenue, which accounts for the bulk of its total revenue, to rise 31% to 32% in the fiscal third quarter to a range of $609 million to $611 million, ahead of forecasts, and 31% in fiscal 2019.

4. -- Toyota to Recall 1 Million Vehicles

Toyota Motor Corp. ( TM said it plans to recall more than 1 million vehicles, including its gasoline-hybrid Prius model, because of an issue with the engine wire harness that can pose a fire risk.

Roughly half of the recalls would take place in Japan, Toyota spokesman Jean-Yves Jault told Reuters.

Only the Prius model would be recalled in the U.S., where around 192,000 vehicles were affected, he said.

5. -- JD.com CEO Was Arrested on Suspicion of Rape

JD.com Inc.  (JD  shares tumbled amid reports that CEO Richard Liu, who was arrested and released last week in Minneapolis, faces an allegation of rape that could bring formal charges as early as Friday, Sept. 7, when a police investigation is complete.

Details of the allegations against Liu, who was released from police custody Sunday after being arrested on a charge of "criminal sexual conduct" and has since returned to China, were revealed in a public disclosure by police in Minneapolis late Tuesday. If charged and ultimately convicted of rape, Liu could face up to 30 years in prison, although his attorney Joseph Friedberg has stressed that there is "no credible complaint" at this stage and police have thus far declined to comment on whether the accuser is co-operating with authorities.

American depositary receipts of JD.com fell 4.6% in premarket trading on Wednesday.

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