Japanese flea market app Mercari soared Tuesday as it debuted on the Tokyo Stock Exchange, a major success for the rare example of a Japanese "unicorn" -- a start-up valued over $1 billion.
The company initially priced its stock at 3,000 yen ($27.30) a share, at the top of a prospective range.
But that price was quickly surpassed on Tuesday, with shares trading around 5,300 yen at midday, putting the firm's value at over 700 billion yen ($6.37 billion).
The online marketplace, started in 2013, allows users to buy and sell everything from clothes and electronic goods to event tickets.
It has attracted international attention for its steady growth, saying it has around one million products on sale on any given day, and generates $100 million a month in transactions globally.
The app has tapped into a relatively new but vibrant market in Japan for second-hand goods, which has also seen brick-and-mortar stores specialising in used books and electronics thrive.
Founder Shintaro Yamada has said the idea for the app came to him as he travelled abroad and saw the appetite for used goods and the power of mobile shopping.
Mercari has already begun expanding overseas, launching in the United States in 2014, and in Britain in 2017, and is expected to plough some of the funds raised by its share offering into further international expansion.