Japan's Topix index jumped 1.9 per cent Monday with export-oriented issues bolstered by a weaker yen. The Topix was up 19.48 points, or 1.9 per cent, at 1,039.98 while the benchmark Nikkei 225 Stock Average gained 65.43 points, or 0.53 per cent, to trade at 12,349.05. Exporters traded broadly higher as the yen fell against major currencies. A weaker yen makes Japanese goods more competitive overseas and improves repatriated earnings, according to a report of DPA.