The main TAIEX index jumped 85.83 points to 7,178.87, its highest closing level since mid-November. Electronics was up 0.98 percent and financial advanced 1.65 percent. AU Optronics, whose shares had tumbled last year due to losses for quarters, soared by the 7 percent limit allowed in one session. "The uncertainty of who wins the vote still remains," said Alex Hu, a vice president at Mega Securities' proprietary trading department. "Investors figure that beaten shares including AU are safe due to their limited downside." Taiwan holds the elections on Jan 14 in a vote that will determine whether the island deepens economic integration with mainland China or embarks on a period of more tense and possibly fractious relations. UMC, the world's No.2 contract chip maker and a market heavyweight, ended up 3.1 percent after releasing its December sales results.