The firm shares were initially priced at 160 pence each in the IPO, with the offer comprising 108,264,032 existing shares, representing 26.6 percent of the company’s issued share capital immediately following admission.

The firm says the offer will raise total net proceeds of approximately £169.3m for the selling shareholders.

The £651m valuation was in the middle of its estimate at the end of last month, which stated it would be between £626m and £675m.

Conditional dealings in the shares commenced on the London Stock Exchange this morning with the shares trading at a premium of close to 35% at a peak of more than 214 pence per share

Admission is expected to become effective, and unconditional dealings in the shares are expected to commence on the London Stock Exchange, at 8am on 12 December.

Andy Bell, chief executive, said: “The IPO is a significant milestone for the business and I see it as firing the starting gun on our next phase of growth, which I’m massively excited about leading the business through.

“The demand for our IPO from both blue chip institutions and our own customers was a real endorsement of our business and the market opportunities that lie ahead of us and I’m pleased to welcome our new shareholders on board.

“I’d also like to thank our employees who do so much day in, day out to ensure we deliver great service to our customers and help them to invest.”