For all the buzz the San Francisco company has created as the preferred platform for U.S. President Donald Trump and other high-profile figures, Twitter has lost more than $1.5 billion cumulatively since it went public in late 2013. Fourth-quarter revenue of $717 million was well short of analysts' expectations. The company is "trapped" and could see declining revenue for another year or two, RBC Capital Markets analyst Mark Mahaney said in a client note.