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Here are five things you must know for Tuesday, April 30:

1. -- Stock Futures Mixed on China Manufacturing Weakness, Google Miss

U.S. stock futures were mixed on Tuesday and global stocks were lower as investors reacted to renewed weakness in China's manufacturing sector and after Alphabet  (GOOGL - Get Report)  posted its weakest revenue gains since 2016.

The big miss for the parent of Google was coupled with a softer-than-expected reading for activity in China's manufacturing sector, which continues to expand but only at a very modest pace, setting up bets on fresh stimulus from Beijing as officials meet with U.S. Trade Representative Robert Lighthizer and Treasury Secretary Steve Mnuchin in the latest round of U.S.-China trade talks.

Contracts tied to the Dow Jones Industrial Average rose 1 point, futures for the S&P 500 slipped 1.40 points, and Nasdaq futures were down 10 points.

The economic calendar in the U.S. Tuesday includes the Employment Cost Index for the first quarter at 8:30 a.m. ET, the S&P Corelogic Case-Shiller Home Price Index for February at 9 a.m., Chicago PMI for April at 9:45 a.m., Consumer Confidence for April at 10 a.m., and the Pending Home Sales Index for March at 10 a.m.

The Federal Reserve will begin a two-day meeting on Tuesday. It's widely expected the central bank will hold steady on interest rates when it announces its decision Wednesday afternoon.

2. -- Alphabet Sinks After First-Quarter Revenue Come Up Short

Alphabet fell 7.9% to $1,193.30 in premarket trading after the online ad giant reported first-quarter revenue that missed Wall Street expectations.

Revenue in the period was $36.34 billion, below forecasts of $37.3 billion. Excluding traffic acquisition costs, Alphabet reported revenue of $29.48 billion, up 19% from a year earlier but below estimates of $30.04 billion. Earnings of $11.90 a share topped Wall Street forecasts of $10.60.

The per-share earnings figures backed out the impact of a $1.7 billion fine imposed by the European Union that Alphabet said it would be booking during the quarter.

Net income in the first quarter was $6.66 billion, which included the EU fine for Alphabet's skirting of antitrust practices and abusing its dominant position in online advertising to hurt competitors.

"We delivered robust growth led by mobile search, YouTube, and Cloud with Alphabet revenues of $36.3 billion, up 17% vs. last year, or 19% on a constant currency basis," said Ruth Porat, Alphabet's chief financial officer. ""We remain focused on, and excited by, the significant growth opportunities across our businesses."

Porat suggested recent ad product changes were affecting Alphabet's top-line growth. She didn't elaborate on what those changes involved, but did say that such moves were made with the long-term interests of users and advertisers in mind, and that the company wasn't interested in managing quarterly numbers.

"Overall, the results appear to look solid but not much more, said Jim Cramer and the Action Alerts PLUS team, which holds Alphabet in its portfolio. "There are positives here, such as the moderating TAC rate and progress in expense control - two areas that have been a source of weakness in quarters of the past.

"However, the revenue figure was too light and we didn't get enough insight into the company's next wave of growth initiatives (YouTube, Cloud, Waymo) to offset the temporary sluggishness," the AAP team added.

3. -- Apple, Advanced Micro Devices, GE and GM Lead Tuesday's Earnings Calendar

General Electric  (GE - Get Report) posted stronger-than-expected first-quarter earnings and confirmed its full-year guidance as new CEO Larry Culp moves toward steadying the financial fortunes of the former Dow component.

Shares of GE rallied 7.6% to $10.47 in premarket trading.

Earnings reports also are expected Tuesday from Apple (AAPL - Get Report) , Advanced Micro Devices (AMD - Get Report) , McDonald's (MCD - Get Report) , Pfizer (PFE - Get Report) , General Motors (GM - Get Report) , Eli Lilly (LLY - Get Report) , ConocoPhillips (COP - Get Report) , Merck & Co (MRK - Get Report) , Phillips 66 (PSX - Get Report) , Amgen (AMGN - Get Report) , Sprint (S - Get Report) , Charter Communications (CHTR - Get Report) , Corning (GLW - Get Report) , Kraft Heinz (KHC - Get Report) , Mastercard (MA - Get Report) , Groupon (GRPN - Get Report) , Twilio (TWLO - Get Report) and Seagate Technology (STX - Get Report) .

Apple and Amgen are holdings in Jim Cramer's Action Alerts PLUS member club. Want to be alerted before Jim Cramer buys or sells the stocks? Learn more now.

4. -- Profit at Oil Giant BP Tops Estimates

U.K. oil giant BP (BP - Get Report) said underlying replacement cost profit in the first quarter fell to $2.4 billion from $2.6 billion a year earlier but came in slightly above analysts' expectations.

First-quarter revenue was $67.4 billion, down 2.5% from a year earlier.

"BP's performance this quarter demonstrates the strength of our strategy," CEO Bob Dudley said in a statement. "With solid upstream and downstream delivery and strong trading results, we produced resilient earnings and cash flow through a volatile period that began with weak market conditions."

BP's downstream earnings in the quarter were $1.73 billion vs. $1.83 billion a year earlier.

Operating cash flow, excluding Gulf of Mexico oil spill payments of $600,000, was $5.9 billion.

Oil and gas production in the quarter rose 2% from the same period in 2018.

BP is a holding in Jim Cramer's Action Alerts PLUS member club. Want to be alerted before Jim Cramer buys or sells BP? Learn more now.

5. -- Western Digital Slumps After Missing Earnings Expectations

Western Digital (WDC - Get Report)  tumbled in premarket trading Tuesday after the data storage devices maker missed fiscal third-quarter earnings expectations.

Adjusted earnings in the quarter were 17 cents a share, well below forecasts of 46 cents. Revenue of $3.67 billion missed analysts' estimates of $3.68 billion. 

The stock fell 4.3% in premarket trading to $48.30. 

"Market conditions have generally been consistent with our expectations, and while the business environment remains soft, there are initial indications of improving trends," said Steve Milligan, CEO of Western Digital. "Our expectation for the demand environment to further improve for both flash and hard drive products for the balance of calendar 2019 is largely unchanged."