Updated from 6 a.m. EDT
 
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Here are five things you must know for Thursday, May 18:
 
1. -- U.S. stock futures declined and European shares fell sharply Thursday following a report from Reuters that said former National Security Adviser Michael Flynn and others in Donald Trump's presidential campaign had extensive contacts with Russian officials.
 
Stocks on Wednesday saw their worst losses of the year. The S&P 500 dropped 1.8%, the Dow Jones Industrial Average fell 1.8%, or 372 points, and the Nasdaq slid 2.6%. The S&P 500's loss was the worst since Sept. 9.
 
The Trump scandal that provoked Wednesday's selloff was the second of the week: A New York Times report that Trump asked former FBI Director James Comey to shut down the federal investigation into Flynn, who was forced to resign on Feb. 13 amid questions over his contact with the Russian ambassador and discussions of U.S. sanctions.
 
The Reuters report on Thursday, which cited unnamed sources, said that Flynn and other advisers to Trump had at least 18 undisclosed contacts with Russian officials and people with ties to the Kremlin in the final seven months of Trump's election campaign. 
 
The report follows news Wednesday that the U.S. Department of Justice named former FBI Director Robert S. Mueller to head a probe into allegations that Russia interfered in last year's presidential elections and to investigate any ties between the Trump campaign and Moscow.
 
The economic calendar in the U.S. on Thursday includes weekly Jobless Claims at 8:30 a.m. EDT, the Philadelphia Fed Business Outlook Survey for May at 8:30 a.m., and Leading Indicators for April at 10 a.m.
 
Walmart ( WMT)  earned $1 a share in the first quarter, 4 cents ahead of estimates. Sales in the period were $117.5 billion, just below forecasts of $117.8 billion.
 
Walmart said same-store sales in the U.S. rose 1.4%.
 
The world's largest retailer said it expects second-quarter earnings of $1 to $1.08 a share, excluding certain items. 
 
The stock rose 0.7% in premarket trading.
 
Others earnings on Thursday's docket include  Bon-Ton Stores ( BONT) , Gap ( GPS) , Ralph Lauren ( RL) , Ross Stores ( ROST) , Alibaba ( BABA) and Salesforce.com ( CRM) .
 
2. -- Facebook ( FB) was fined €110 million ($122.5 million) by European Union antitrust regulators for providing misleading information related to its 2014 acquisition of WhatsApp.
 
The European Commission said Facebook insisted on two separate occasions that it couldn't establish a reliable automated match between user accounts of both platforms. However, a subsequent update to the company's terms of service and privacy policy indicated such a link was possible.
 
"Today's decision sends a clear signal to companies that they must comply with all aspects of EU merger rules, including the obligation to provide correct information," said Commissioner Margrethe Vestager. "And it imposes a proportionate and deterrent fine on Facebook. The commission must be able to take decisions about mergers' effects on competition in full knowledge of accurate facts."
 
The commission has the authority to fine companies a sum equivalent to 1% of annual turnover which, in Facebook's case, could have amounted to $276 million based on its reported 2016 revenue total of $27.638 billion.
 
However, the commission said that while Facebook "committed two separate infringements by providing incorrect and misleading information in the merger notification form and in the reply to a commission request for information" it also "acknowledged its infringement of the rules and waived its procedural rights to have access to the file and to an oral hearing. This allowed the commission to conduct the investigation more efficiently."
 
Facebook said the errors made in its 2014 filings weren't intentional. "Today's announcement brings this matter to a close," Facebook said in a statement.
 
The stock fell 0.6% in premarket trading on Thursday.
 
Facebook is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells FB? Learn more now.

3. -- Fiat Chrysler  (FCAU) shares tumbled in Milan as the heat from emissions probes on both sides of the Atlantic intensified.

Shares were down more than 6%, marking the biggest one-day fall for the stock since January and bringing total losses for the last seven days to 14.1%.

The slump follows reports that the U.S. Department of Justice is preparing a civil suit against the carmaker following a probe that was opened in January related to excess diesel emissions. Fiat Chrysler was accused by the U.S. Environmental Protection Agency of failing to disclose engine management software in its vehicles, including Jeep Cherokee and Dodge Ram trucks, which could result in an emissions output that was too high. 

In a statement, Fiat Chrysler said that "in the case of any litigation, FCA US will defend itself vigorously, particularly against any claims that the company deliberately installed defeat devices to cheat U.S. emissions tests."

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4. -- Cisco ( CSCO)  shares fell 8% in premarket trading Thursday after the networking giant issued weaker-than-expected guidance for the fourth quarter.
 
Cisco is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells CSCO? Learn more now.
 
Cisco earned 60 cents a share in its fiscal third quarter, exceeding Wall Street expectations of 58 cents. Revenue of $11.94 billion topped forecasts of $11.89 billion.
 
But the company said it expects fiscal fourth-quarter revenue to be down 4% to 6% from the prior year, compared to consensus estimates for revenue to be down 1% to $12.52 billion. Earnings guidance of 60 cents to 62 cents a share compared with analysts' expectations of 62 cents.
 
Cisco also said it was laying off 1,100 more workers, cuts that come on top of the 5,500 jobs Cisco announced it was eliminating in August amid declines in revenue.
 
5. -- Sirius XM ( SIRI) is in active discussions about making a bid for internet radio company Pandora Media ( P) , according to the New York Post.

The New York satellite radio company recently restarted talks with Pandora's banks and is discussing the size of a potential offer, sources said.

There is no agreement yet on a price, but one optimistic industry insider believes a bid could range as high as $12 to $13 a share.

That price tag was immediately shot down by sources familiar with talks, the Post reported.

Pandora shares jumped in premarket trading Thursday by 6.5% to $9.51.

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