Tokyo stocks rebounded sharply Wednesday, snapping the Nikkei index’s three-day losing streak, on buybacks of technology shares and gains in export-related issues amid a weaker yen. The 225-issue Nikkei Stock Average ended up 670.08 points, or 2.04 percent, from Tuesday at 33,445.90. The broader Topix index finished 44.51 points, or 1.90 percent, higher at 2,387.20. On the top-tier Prime Market, gainers were led by precision instrument, electric power and gas, and securities house issues.