Tokyo Metro shares surge 45% on debut after Japan's largest IPO in six years

Shares of Japanese subway operator Tokyo Metro closed 45% higher Wednesday after a stellar IPO.

The company had raised 348.6 billion yen ($2.3 billion) in the largest initial public offering in Japan in six years. Shares were priced at the top-end of the IPO price band of 1,100 yen to 1,200 yen.

Tokyo Metro is one of Japan's leading subway companies and the largest operator in Tokyo. The company is currently owned jointly by Japan's national government and the Tokyo metropolitan government, with a 53.4% and 46.6% stake respectively.

Reuters reported that the overall IPO was oversubscribed more than 15 times, while the portion available to retail investors — almost four-fifths of the overall size — was oversubscribed around 10 times.

The shares available to domestic and foreign institutional investors, accounting for 1.5% and 20% respectively, were oversubscribed more than 20 and 30 times, Reuters reported.

Jesper Koll, expert director at financial services firm at Japan-based Monex Group in Tokyo, said the IPO was warmly received due to the company being a "cash cow." Tokyo Metro is a "high dividend, stable cash flow generator," and the company has a very low operational risk, he added.

"So whether you're Mr. Watanabe [retail investor] ... whether you're the global investor or an institutional investor, this is a great share to own."

Koll also pointed out that Tokyo Metro's dividend outlook is "very stable," and may even see a little upside.

This is because the demand for metro service in Japan's capital remains very strong, and Tokyo's population grows at almost 1% every year, he added.

Mio Kato, founder of LightStream Research, told CNBC's "Street Signs Asia" last week that the stock has been priced "relatively cheaply,"