It has no High Street shops and few people over the age of 40 will have even heard of it. But online fashion retailer Boohoo is instantly recognisable to teenagers and twentysomethings everywhere.

And thanks to its remarkable ability to replicate celebrity fashion trends in a matter of days, it’s one of the most extraordinary British success stories of recent times.

The brand has humble origins on a Manchester market stall but it is now worth £2.6 billion – almost five times as much as Debenhams – after the shares surged tenfold over the past two years.