By TheStreet Staff The Arena Group, publisher of Sports Illustrated, TheStreet, Parade and more, reported that Q2 gross profit, revenue and digital-ad revenue jumped. The Arena Group Holdings (AREN) – Get The Arena Group Holdings Inc. Report, the New York tech-driven publisher of Sports Illustrated, TheStreet, Parade and more, reported that second-quarter gross profit nearly doubled on 87% higher revenue. Digital ad revenue more than doubled, “driven by traffic improvements of 82% and an over 40% growth in display [cost per thousand impressions],” the company said in a statement. “The Arena Gr…