NEW YORK (TheStreet) -- Shares of EMC (EMC) jumped by 1.8% Monday, closing at $28.35, after Dell announced that it would buy the Hopkington, Mass.-based data storage company for $67 billion in the biggest tech deal ever.

But VMware(VMW) - Get Report , which is majority-controlled by EMC, dropped by 8.1% amid concerns that a tracking stock that will be issued for VMware could dilute that company's value. VMware, which closed Monday at $72.28, is based in Palo Alto, Calif.

Dell CEO Michael Dell and EMC CEO Joe Tucci discussed the deal on CNBC. They said it would benefit shareholders of both EMC and VMware.

The complicated financial transaction would be valued at $33.15 per share for EMC shareholders. It would include $24.05 in cash to EMC shareholders, plus a tracking stock for EMC's 81% stake in VMware. It would also include a significant amount of debt. Read TheStreet's report of the deal.

Dell, who founded his Texas-based company in his dormitory room at University of Texas in Austin more than 30 years ago, told CNBC he expects to see "a significant reduction in debt" within the first 18 to 24 months of the deal. He said that would come from a combination of sources, including the cash flow of the combined companies, as well as "cost synergies and revenue synergies."

Hedge fund Elliott Management has been urging EMC to find more value for its shareholders.

By acquiring EMC, Dell will continue to diversify from its roots as a made-to-order PC manufacturer to a provider of a wide array of business services. The company, which was taken private two years ago, will remain headquartered in Round Rock, a suburb of Austin.

Like Apple(AAPL) - Get Report  co-founder Steve Jobs, Michael Dell is a college dropout. 

Twitter(TWTR) - Get Report dropped by 6.8% Monday, closing at $28.74. The company is planning company-wide layoffs, possibly as early as Tuesday, Re/code reported on Friday after the markets closed. The San Francisco micro-blogging site has about 4,100 employees.

Twitter co-founder Jack Dorsey was named permanent CEO of the company just last week. He had been serving as interim CEO for about three months.

Wall Street often applauds layoffs at a company, even though the move is obviously difficult for employees who are affected. It can signal that management is serious about controlling its costs.

In the case of Twitter, though, some analysts and investors remain concerned about the direction of the company, its ability to grow revenue and the continued disruption that layoffs will cause. Read TheStreet's report on why Twitter stock got slammed today. 

Tesla Motors(TSLA) - Get Report stalled again on Monday, dropping by 2.3% to $215.58 after falling by 2.7% Friday. The company's shares were downgraded by three analysts last week amid concerns about its financial challenges, as well as its Model X rollout.

Separately, the electric car manufacturer announced that an autopilot mode for its Model S will be released Thursday, SiliconBeat reported.

Alphabet's(GOOGL) - Get Report  Google unit will invest $100 million in Symphony Communication Services along with several other investors, Reuters reported.

Symphony, a messaging startup backed by several Wall Street banks, "allows financial firms, corporate customers and individuals to put all of their digital communications on one centralized platform," the news service said. Shares of Alphabet rose by about 1% Monday to $676.43.

Facebook(FB) - Get Report stock rose by 1.1% Monday, closing at $94.26.

The company is diving deeper into e-commerce with new shopping features. Read the complete report by TheStreet's Rebecca Borison.

Separately, Facebook messaging chief David Marcus was interviewed at Re/code's Code/Mobile conference in Half Moon Bay, Calif. Check out the video of Re/code's complete interview with Marcus.

Shares of Etsy(ETSY) - Get Report plummeted by 11.2% Monday, ending the day at $12.31 -- the company's lowest close ever, TheStreet reported.

The company is facing intense competition from Amazon(AMZN) - Get Report . Amazon shares finished the day at $550.19, up by 1.9%.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.