Here are five things you must know for Wednesday, March 14: 

1. -- Stocks Rise but Markets Are on Edge  

U.S. stock futures were in positive territory on Wednesday, March 14, but investors were growing increasingly concerned over the prospects of a global trade war following the firing of Rex Tillerson as U.S. secretary of state and reports of new tariffs targeted specifically at China.

Contracts tied to the Dow Jones Industrial Average rose 92 points, while those tied to the broader S&P 500 gained 8 points.

Stocks declined on Tuesday, March 13, triggered by the surprise sacking of Tillerson as secretary of state. The Dow Jones Industrial Average finished down 171 points, or 0.68%, to 25,007. The S&P 500 slipped 0.64% and the Nasdaq fell 1.02%.

Asian stocks finished lower on Wednesday following the dismissal of Tillerson, who was seen as a moderate voice on trade and foreign relations inside the White House, and a report from Reuters that Trump was targeting consumer technology and telecoms goods from China with a series of tariffs that could hit $60 billion in goods from the world's second-largest economy.

The economic calendar in the U.S. on Wednesday includes the Producer Price Index for February at 8:30 a.m. ET, Retail Sales for February at 8:30 a.m., and Oil Inventories for the week ended March 9, at 10:30 a.m.

Earnings are expected Wednesday from Williams-Sonoma Inc. (WSM) , Vera Bradley Inc. (VRA) and Express Inc. (EXPR) .

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2. -- Walmart Expands Home Delivery of Groceries

Walmart Inc. (WMT) said Wednesday it would expand home delivery of groceries to more than 40% of U.S. households by the end of the year.

The service, which already is available in six markets -- Phoenix, Dallas, Orlando, Tampa, Denver, and San Jose -- will grow to serve more than 100 metro areas across the country, Walmart said in a press release. 

"We're serving our customers in ways that no one else can," said Greg Foran, president and CEO, Walmart U.S. "Using our size and scale, we're bringing the best of Walmart to customers across the country."

Walmart will provide the locations of the new markets as service begins over the next few weeks.

Under the new program, online grocery orders will be packed in a Walmart store by company workers and then handed off to a delivery company or startup that uses contract workers to bring orders to homes, a Walmart spokesman told The Wall Street Journal. Uber Technologies Inc. will be one of the initial partners, expanding a test started in 2016. 

The stock rose 0.15% in premarket trading.

3. -- Google to Ban Bitcoin Advertisements

Bitcoin fell nearly 4% early Wednesday to $8,772 after Alphabet Inc.'s (GOOGL) Google said it would stop running ads for initial coin offerings and trading platforms, a move that mimics a similar ban announced by Facebook Inc. (FB) earlier this year.

In a blog post, Scott Spencer, Google's director of sustainable ads, said Wednesday the company has "updated several policies to address ads in unregulated or speculative financial products like binary options, cryptocurrency, foreign exchange markets and contracts for difference (or CFDs)."

Alphabet and Facebook are holdings in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells the stocks? Learn more now.

4. -- Broadcom to Formally Abandon Bid for Qualcomm

Broadcom Ltd.  (AVGO) abandoned its attempt to acquire rival chipmaker Qualcomm Inc.  (QCOM)  after Donald Trump blocked the deal on national security concerns.

Broadcom also said it withdrew its nominees for Qualcomm's board of directors.

Trump said late Monday, March 12, that he was denying Broadcom's takeover of Qualcomm.

"There is credible evidence that leads me to believe that Broadcom Limited, a limited company organized under the laws of Singapore (Broadcom) ... through exercising control of Qualcomm Incorporated (Qualcomm), a Delaware corporation, might take action that threatens to impair the national security of the United States," a statement from the White House read as Trump effectively blocked the contentious merger battle between the two tech titans.

Qualcomm shares rose 0.9% in premarket trading. Broadcom was inactive. 

Broadcom is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells AVGO? Learn more now.

5. -- Physicist Stephen Hawking Dies

Stephen Hawking, the best-known theoretical physicist of his time, died early Wednesday, a University of Cambridge spokesman said. He was 76 years old.

Hawking, who was diagnosed in 1962 with Amyotrophic Lateral Sclerosis, more commonly called ALS or Lou Gehrig's disease, died at his home in Cambridge, England.

Hawking's book, "A Brief History of Time," became an international best seller, making him one of science's biggest celebrities since Albert Einstein.

This article has been updated with information on Broadcom's withdrawal of its bid for Qualcomm.

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