Shares of EMC are down 40 cents, or 2%, at $18.47, after the company this morning said it will spend $1.2 billion in cash to buy six-year-old Bethesda, Maryland-based startup Virtustream , which runs cloud computing services for enterprises. EMC said Virtustream's focus on managing big applications for companies such as SAP programs, will extend the work that EMC already does with so-called "private cloud," where it simply sells infrastructure to companies for them to reorganize how they run those apps in their facilities.