Shares of General Electric Co. shot up 3.9% to a one-month high in morning trade Wednesday, to extend the previous session's biggest gain in three years, after Oppenheimer upgraded the industrial conglomerate, citing optimism over the company's break-up plan. The stock has now run up $1.52, or 12%, since it exited the Dow Jones Industrial Average effective after Monday's close, when the stock closed at a 9-year low of $12.75. Meanwhile, shares of GE's replacement in the Dow, Walgreens Boots Alliance Inc. have inched up 9 cents, or 0.1%, since it has entered the Dow. Based on the new Dow divisor, Walgreens stock has added about 1 point to the Dow since it became a component--the Dow is up 172 points over the same time--while GE's stock would have added 10 points to the Dow.