The company, which helps sell retail brands, including Lookfantastic and skincare group ESPA, sold 376 million shares at 500 pence each to raise 1.88 billion pounds.
The biggest London stock market debut by market cap since Royal Mail in 2013 nets the company 920 million pounds while shareholders, led by founder Matthew Moulding and private equity group KKR, will share gross proceeds of 961 million pounds. KKR sold its entire shareholding.
The shares were trading at 646 pence at 1040 GMT.
Analysts suggested the stock surge might prompt some questions as to whether the deal was pegged at the right price.
"Time will tell as to whether the valuation is a solid one, or whether KKR has made the right move in selling out of their entire stake," CMC markets analyst Michael Hewson said.
While The Hut Group's debut gave a boost to a terrible 2020 for new listings, with the COVID-19 pandemic driving European IPO volumes to their lowest since 2012, the unusual structure of the deal has raised some concerns among corporate governance watchers.
For example, Moulding will remain both chairman and chief executive of the company, while the company shares are to be issued in different "classes", allowing him voting powers vastly superior to most London-listed companies.
"They are completely separate roles and (combining the two) undermines the board's primary duty, which is to challenge the CEO," Francisco Lopez de Saa, stewardship director at Minerva Analytics, said.
He said the offering of different share classes was unsuitable for the UK market and reduced the protection of minority shareholders.
This structure means that The Hut Group will not achieve a so-called premium listing and will not be eligible for the FTSE 100 despite being big enough for the blue-chip index. The London Stock Exchange declined to comment.
One source close to the deal said the LSE standard listing required high levels of governance and was equivalent to other European exchanges.
BlackRock, Henderson Global Investors, funds managed by Merian and the Qatar Investment Authority agreed to buy 565 million pounds of the shares offered.
"There wasn't too much concern about this during the bookbuild - investors understand that the founder is a key part of the story," said a second source familiar with the transaction.
He said companies would take heart from THG's success and launch deals this year. "We expect a busy fourth quarter."Citi, JP Morgan, Barclays and Goldman Sachs were global coordinators. HSBC, Jefferies and Numis acted as joint bookrunners. Rothschild advised the company.
By Abhinav Ramnarayan and Sinead Cruise