Cigna Corp. shares surged as much as 19 percent after Anthem Inc. was reported to be pursuing a takeover of its smaller health-insurance rival. Cigna rose to $156.38 at 1:07 p.m. in New York after earlier reaching $164. Anthem has made two takeover bids within the past 10 days for Cigna, which rebuffed the latest offer for about $175 a share, the Wall Street Journal reported, citing people familiar with the discussions.