TOKYO, Feb. 15 (Xinhua) -- Tokyo stocks opened higher Thursday tracking gains on Wall Street overnight, with investors' risk appetite returning to the market.

As of 9:15 a.m. local time, the 225-issue Nikkei Stock Average gained 283.77 points, or 1.34 percent, from Wednesday to 21,437.94.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, added 21.36 points, or 1.25 percent, at 1,724.08.

Bank, insurance and mining-oriented issues comprised those that gained the most in the opening minutes after the morning bell.