Each week, I'm ranking the biggest companies that trade on U.S. exchanges based on their size (market capitalization), momentum (total return over the past year), and recent news. Before we get to the rankings, a quick word on a major player.

It's not easy being Facebook (NASDAQ:FB) these days. The stock has shed more than a fifth of its value, and investors continue to be concerned about the social networking giant's ability to spruce up its reputation as data privacy fears intensify. 

Thankfully for investors, there's more to Facebook than its namesake site. It owns several platforms that are holding up considerably better than its flagship platform, and Facebook may be ready to cash in on the success of its sister projects. The New York Times reports that that Facebook plans to mesh its WhatsApp, Instagram, and Messenger platforms together. The three services will continue to run on their own, but the messaging infrastructure will be unified as early as next year. 

With that in mind, let's review this week's updated list of 50 top large-cap stocks, kicking things off with the top 10.

Marble bull and bear squaring off in battle.

Image source: Getty Images.

This week's top 10 stocks

10. Walmart (NYSE:WMT): $281.6 billion, down 9.1% over the past year.

The leading retail chain moved higher on the week after a couple of positive analyst moves. Capital One (NYSE:COF) also discussed its agreement to acquire the existing portfolio of Walmart's co-branded and private-label credit card receivables. Capital One is taking on roughly $9 billion in receivables in the process, building on long-term credit card agreement that the two companies entered into over the summer. 

9. Pfizer (NYSE:PFE) (down from 7): $234.9 billion, up 9.2%.

The pharmaceuticals giant is sliding down a few notches this week, after an analyst downgraded the stock. Navin Jacob at UBS is lowering his rating on Pfizer from "buy" to "neutral," slashing his price target from $48.50 to $46. He thinks the stock's valuation is less compelling than it was in his previously bullish update.

8. Alibaba (NYSE:BABA) (up from 9): $412.7 billion market cap, down 19.7%. 

China's leading online marketplace was treated to dueling analyst notes. Baird lowered its estimates for Alibaba on Tuesday, pointing to the deceleration of online sales in China given its slowing economy. Rob Sanderson at MKM Partners followed with a rosier outlook later in the week, arguing that margin pressure will reverse this year. He continues to tag Alibaba as his top pick among the megacap stocks. Both analysts do have bullish ratings on the stock, but their price targets are $67 apart. 

7. Facebook (up from 8): $428.2 billion market cap, down 20.5%.

The social-networking leader will get a good chance to move during the week ahead. It reports fourth-quarter results on Wednesday, and at least one Wall Street pro is looking forward to the fresh financials. Doug Anmuth at J.P. Morgan put out a positive note on Facebook ahead of its report, seeing continuing strength at Instagram and easier comparisons for Facebook itself when it comes to time spent on the platform when pitted against the prior year's shocking slowdown. 

6. Visa (NYSE:V): $ 305.7 billion, up 10.7%.

It's earnings season, and the world's leading credit card company is expected to post another period of double-digit growth on both ends of its income statement on Wednesday. Analysts see Visa checking in with $5.4 billion in revenue for the quarter, 11% ahead of where it was a year earlier. They see profits growing even faster, with earnings per share rising 16% to $1.25. The cashless revolution continues to gain traction. 

5. Berkshire Hathaway (NYSE:BRK-A): $498.8 billion, down 6%.

A Berkshire Hathaway subsidiary hoping to produce lithium for batteries has come under fire. A Financial Times report raised some doubts about the technological process in extracting lithium from California geothermal wells. Berkshire Hathaway's market cap also dipped below $500 billion.

4. Apple (NASDAQ:AAPL): $746.2 billion, down 7.8%.

All eyes will be on Apple when it reports its fiscal first-quarter results on Tuesday. Apple has already confirmed that iPhone sales were sluggish during the holiday-containing quarter, and the stock continues to trade lower over the past year. Wall Street's views are mixed ahead of the numbers. William Power at Baird is cautious, arguing that the consensus estimates may still be too high given the continuing challenges in China and even its home market. Katy Huberty at Morgan Stanley thinks the pessimism is running thick, giving Apple a lower bar to clear in impressing investors on Tuesday.

3. Alphabet (NASDAQ:GOOG) (NASDAQ:GOOGL): $762.4 billion, down 6.8%.

Stifel analyst Scott Devitt is lowering his price target on Alphabet from $1,400 to $1,300. He thinks Google's parent company turned in a solid fourth quarter, but he sees revenue growth and margins in the year ahead coming in slightly below his earlier forecast. Several ad agencies have been lowering their global growth projections for 2019, and Devitt thinks the reduced spending will affect Alphabet's core online business. He's still bullish on Alphabet but more cautious about the stock's near-term prospects for appreciation.  

2. Amazon.com (NASDAQ:AMZN) (down from 1): $816.9 billion, up 21.2%.

Amazon is always looking for ways use high-tech to improve its efficiency, and its latest project is an autonomous delivery system. Amazon Scout is designed to get packages to its customers through autonomous devices that are about the size of a small cooler, rolling along sidewalks at a walking pace. They can navigate around pets, pedestrians, and anything else in their way. The first test of the high-tech delivery platform began this past week in a Snohomish County neighborhood in its home state of Washington.

1. Microsoft (NASDAQ:MSFT) (up from 2): $822.8 billion, up 16.1%.

Mr. Softy is on top again. It's overtaken Amazon in market cap since last week, and while its trailing return is slightly less, we continue to reward momentum here. On the downside, Bing suffered a brief hiccup in China, leaving the online search engine inaccessible earlier in the week. 

The rank and file

We'll get to No. 11 through No. 50 in a moment, but first, let's look at one of the other Top 50 stocks making waves, for better or worse.

In a story involving four members of our top 50, UnitedHealth Group's (NYSE:UNH) Optum unit is suing a former IT executive who left to help get a rival concept off the ground. Amazon, Berkshire Hathaway, and JPMorgan Chase (NYSE:JPM) hired David Smith to help revolutionize the healthcare industry. UnitedHealth thinks the hire is a threat to Optum's trade secrets and other confidential information. 

The lawsuit claims Smith was attending strategy meetings at UnitedHealth and seeking out confidential information from employees even as it was interviewing for the new Amazon-helmed venture. It also says Smith printed an Optum document that was marked as confidential a minute before printing his resume. That's cold if true. We'll see how this story plays out in the coming weeks.

Stocks 11 through 50

11. Johnson & Johnson (NYSE:JNJ): $343.9 billion, down 11.2%.

12. JPMorgan Chase: $343.8 billion, down 10.6%.

13. Merck & Co. (NYSE:MRK): $189.7 billion, up 19%.

14. UnitedHealth Group (NYSE:UNH): $257.9 billion, up 9.3%.

15. Mastercard (NYSE:MA): $209.6 billion, up 20.4%.

16. Procter & Gamble (NYSE:PG): $234.1 billion, up 6%.

17. Verizon (NYSE:VZ): $233 billion market cap, up 3.9%.

18. Intel (NASDAQ:INTC): $214.7 billion, up 3.8%.

19. Netflix (NASDAQ:NFLX): $147.4 billion, up 25.3%.

20. Cisco (NASDAQ:CSCO): $207.4 billion, up 10.1%.

21. ExxonMobil (NYSE:XOM): $303.6 billion, down 18.8%.

22. Bank of America (NYSE:BAC): $286 billion, down 7.8%.

23. Boeing (NYSE:BA): $206.8 billion, up 6.2%.

24. Royal Dutch Shell (NYSE:RDS-A): $243.2 billion, down 9.6%.

25. Novartis (NYSE:NOV): $199.2 billion, down 1.9%.

26. Coca-Cola (NYSE:KO): $201.6 billion, down 1%.

27. Walt Disney (NYSE:DIS): $165.6 billion, up 0.5%.

28. Chevron (NYSE:CVX): $216.3 billion, down 13.3%.

29. Home Depot (NYSE:HD): $203.8 billion, down 12.2%.

30. PetroChina (NYSE:PTR): $188.3 billion, down 20.6%.

31. Wells Fargo (NYSE:WFC): $229.7 billion, down 23.6%.

32. AT&T (NYSE:T): $223.1 billion, down 18.1%.

33. McDonald's (NYSE:MCD): $141.8 billion, up 4.8%.

34. Oracle (NYSE:ORCL): $178.7 billion, down 3.5%. 

35. PepsiCo (NASDAQ:PEP): $154.4 billion, down 9.6%.

36. Eli Lilly (NYSE:LLY): $113 billion, up 35.2%.

37. Salesforce.com (NYSE:CRM): $114.6 billion, up 33.7%.

38. Adobe (NASDAQ:ADBE): $119.5 billion, up 24%.

39. Nike (NYSE:NKE): $126.9 billion, up 19.1%.

40. Union Pacific (NYSE:UNP): $118.6 billion, up 20.5%.

41. Abbott Laboratories (NYSE:ABT): $125 billion, up 12.5%.

42. China Mobile (NYSE:CHL): $211.8 billion, down 1.7%.

43. Amgen (NASDAQ:AMGN): $126.7 billion, up 4.6%.

44. GlaxoSmithKline (NYSE:GSK): $93.3 billion, up 7.9%.

45. BHP Billiton (NYSE:BHP): $119.9 billion, up 7.1%.

46. Petrobras (NYSE:PBR): $96.5 billion, up 32.1%.

47. PayPal Holdings (NASDAQ:PYPL): $111.1 billion, up 11.8%.

48. Unilever (NYSE:UL): $139.5 billion, up 0.8%.

49. Costco (NASDAQ:COST): $92.1 billion, up 5.6%.

50. Toyota (NYSE:TM) (new): $175.8 billion, down 10.9%.

Who's in and who's out

Toyota revs its way back onto our list this week. It is the world's most valuable automaker by market cap, and it's the only car manufacturer on the list despite its negative return over the past year. 

Toyota announced last week that it will team up with consumer-electronics giant Panasonic to form a joint venture to make electric-vehicle batteries. Toyota will own 51% of the joint venture. 

The Japanese company also isn't losing sight of its growth prospects in China. Toyota is forecasting 8% growth in China this year, a projection that would call for moving 1.6 million vehicles in a country where the economy is slowing.

Toyota replaces Citigroup (NYSE:C), bumped after a single week on the list. The banking and financial-services giant is certainly large enough to make the list, clocking in at $151.6 billion, but the stock's 19.4% decline over the past year has kept it on the outside looking in. Banking stocks have generally had a good start to 2019, but Citi continues to be a laggard among the financial-services heavyweights.

One to watch

There's a lot going on at Comcast (NASDAQ:CMCSA) these days. The company behind the country's leading cable television and internet service provider, as well as the parent company of NBCUniversal, posted better-than-expected fourth-quarter results last week. It's not losing as many cable television subscribers as its smaller rivals to the cord-cutting revolution, shedding just 29,000 video customers in the fourth quarter, and it more than made up for that loss with the net addition of 351,000 high-speed internet accounts.  

Universal's Glass continues to be the top draw at the local multiplex. Comcast also recently tossed its hat into the streaming ring, announcing a standalone NBCUniversal service that should come out in 2020. 

Comcast is one of the most valuable companies not on the list, as its $162.8 billion market cap is undermined by the stock's 15% slide over the past year. The stock moved higher following Wednesday's encouraging financial report. If the company is able to keep the momentum going, it wouldn't be a surprise if Comcast claws its way back on to the list.  

John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. Suzanne Frey, an executive at Alphabet, is a member of The Motley Fool's board of directors. Teresa Kersten, an employee of LinkedIn, a Microsoft subsidiary, is a member of The Motley Fool's board of directors. Rick Munarriz owns shares of AT&T, China Mobile, Netflix, and Walt Disney. The Motley Fool owns shares of and recommends Adobe Systems, Alphabet (A shares), Alphabet (C shares), Amazon, Facebook, Mastercard, National Oilwell Varco, Netflix, PayPal Holdings, Salesforce.com, and Walt Disney. The Motley Fool owns shares of Johnson & Johnson, Microsoft, Oracle, and Visa and has the following options: short February 2019 $185 calls on Home Depot, long January 2020 $110 calls on Home Depot, and long January 2020 $30 calls on Oracle. The Motley Fool recommends Amgen, Comcast, Costco Wholesale, Home Depot, Nike, Union Pacific, UnitedHealth Group, and Verizon Communications. The Motley Fool has a disclosure policy.