(Bloomberg) — DNA-sequencing company Oxford Nanopore Technologies Ltd. was valued at 3.4 billion pounds ($4.6 billion) in a London share sale that capitalized on a pandemic boost and strong demand for fast-growing tech stocks in the U.K.

Shares in the initial public offering priced at 425 pence each, in the top half of an initial range, according to a statement Thursday. Oxford Nanopore sold 350 million shares of new stock while its backers outsold existing shares valued at 174 million pounds. 

The University of Oxford spinoff’s holders sold more shares in the IPO than planned due to high demand. The Oracle Corp (NYSE:).-backed company provides Covid-19 test kits to Britain’s National Health Service, and its sequencing technology has been used by researchers to characterize the genome of the SARS-CoV-2 virus to identify and track variants. 

Oxford Nanopore has added about $1 billion to its market value since its last funding round in May, placing it among the U.K.’s most valuable startups. The IPO is an important win for London’s ambitions to boost its profile as a hub for innovative businesses.

Gordon Sanghera (the founder of the company and its chief executive officer) has been granted a special type of shares that gives him extra power to stop any unwanted takeovers. Though panned by some investors for diluting voting rights, there are plans to allow multiple classes of shares on the London Stock Exchange’s top-tier premium market.

For now, Oxford Nanopore is relegated to the bourse’s standard segment, which means it is ineligible for certain major benchmarks like the Russell indexes. On Thursday, trading in the stock starts on the LSE.

Bank of America Corp (NYSE:)., Citigroup Inc (NYSE:). and JPMorgan Chase & Co. (NYSE:) are global coordinators of the offering. Barclays (LON:) Bank Plc, Berenberg, Guggenheim Securities, Numis Corp Plc and RBC Capital Markets are joint bookrunners.

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