The Nikkei stock index surged over 2 percent early Monday as investors snapped up battered shares following an eight-day losing streak, also supported by gains on Wall Street late last week and a weaker yen. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average rose 795.24 points, or 2.11 percent, from Friday to 38,462.65. The broader Topix index was up 42.72 points, or 1.58 percent, at 2,742.26. On the top-tier Prime Market, gainers were led by insurance, nonferrous metal and chemical issues.