Tokyo’s benchmark stock index surged from the start of trading on Monday surpassing the 47,000-mark.
That’s another all-time intraday high for the Tokyo Stock Exchange.
The Nikkei 225 shot up more than 2,000 points at one stage, or about 4.8 percent, from Friday’s close.
Investors bought up shares on expectations that the person expected to become Japan’s next prime minister will go easy on fiscal policy.
Takaichi Sanae has been elected head of the main ruling Liberal Democratic Party.
Currency markets were also affected by her win.
The Japanese yen weakened to the 150 level against the dollar at one point from mid-147 yen at the end of last week.
Also, the yen briefly fell to the 176 level against the euro, marking the lowest level since the eurozone’s currency was launched in 1999.
Market sources added that many investors are now paying close attention to Takaichi’s economic policies as well as how her administration will coordinate with the opposition to realize them.