With its stock losing a quarter of its worth in the last year, Tribune Co. may be considering a sale of non-core assets such as the Cubs. That’s the speculation from one of the Tribune’s top-five investors, Chicago-based investment firm Ariel Capital Management. “If their stock gets into the $20s, I think their management would have to look to sell non-strategic assets, including the Cubs,” said John Miller, senior vice president of portfolio management at Ariel, whose firm holds 10 million shares of Tribune stock. Its stock settled up 46 cents on Monday at $31.37. Its 52-week high is $44.32. Non-core Tribune assets include the Food Network, WB Network, CareerBuilder.com and the Cubs, with an estimated value of $2 billion. Core assets would include broadcast stations such as WGN-TV and newspapers such as the Chicago Tribune and the Los Angeles Times. Hello Mark Cuban.