Viking's stock surged in one trading session after a positive clinical trial report last year.Viking Therapeutics (VKTX 0.24%) leaped onto center stage early last year when it announced promising news about a candidate addressing an area of soaring demand: weight loss. The biotech then said its weight loss candidate, VK2735, met the goals of its phase 2 study. Investors realized it would be continuing into later-stage trials -- and the stock price surged more than 120% in one trading session.Viking remains ...