turbo-charged the stock market when its shares debuted yesterday and spiked more than 40%.

Shares in the white goods etailer closed at 378p, 32% higher than the 285p offer price, which valued the business at £1.2bn, and even greater than the record gains made by Royal Mail on its first day of trading last year, the Financial Times reported.

At 1pm shares in spiked to as much as 412.25p, an increase of 44.6% following significant demand from investors for online and technology stocks.

Founder John Roberts made £86m from selling shares ahead of the listing. He retains a 28.6% stake.

Roberts said investors have “understood our business model and our potential. We welcome them as shareholders”.

Some onlookers, including rival Dixons, have criticised the valuation of, calling it over-inflated.