The KOSPI edged higher Wednesday, buoyed by buying from corporate investors as Samsung Electronics and SK hynix stepped up share buyback plans, though cautious trading ahead of Nvidia’s earnings kept gains in check. The benchmark index opened at 6,727.25, down 0.23 percent from the previous session, and moved within a narrow range before picking up momentum in the afternoon. It ultimately closed at 6,808.21, up 0.97 percent. The gain came despite selling by both retail and foreign investors. Retail investors offloaded a net 2.25 trillion won ($1.63 billion) worth of shares, while foreign investors sold 105.2 billion won. Institutional investors, meanwhile, purchased a net 764.9 billion won. Corporate investors — companies that fall outside the individual, foreign and institutional investor categories — were the most notable buyers, purchasing a net 1.6 trillion won. The buying appeared to reflect in part purchases related to the share buyback programs announced by Samsung Electronics and SK hynix. Shares of the two semiconductor heavyweights rose 1.75 percent and 0.6 percent, respe