At least one group of UK residents is flourishing in Brexit Britain: An exclusive club of billionaires.

The 15 Britons on the Bloomberg Billionaires Index have added £21.5bn (€25bn) to their fortunes since the country voted to leave the EU on June 23, 2016, including £14bn so far this year.

Their combined net worth is £83.6bn. Two Brexiteers are responsible for most of the gains.

Jim Ratcliffe and James Dyson, the founder of Dyson Ltd, have added a combined £15bn since the vote, according to the ranking, with Mr Ratcliffe displacing Hugh Grosvenor, the Duke of Westminster, as Britain’s richest person.

That compares to the estimated £39bn (€45.2bn) the UK would need to settle its liabilities with the EU. The growth in their fortunes contrasts with the UK’s wider economic stagnation since the vote.

In February, Bank of England governor, Mark Carney, said the economy was suffering amid the “fog of Brexit”, as the bank downgraded its view on growth for this year and next.

While the labour market remains strong, businesses are cutting spending, fearing an economic slowdown could turn into a severe recession, if the UK leaves the EU without a deal to cushion the blow.

Britain’s richest have been able to navigate such uncertainties. They are an increasingly footloose breed. More than half the British entrepreneurs on the Bloomberg ranking are no longer UK residents.

In February, the Sunday Times reported that Mr Ratcliffe, 66, was examining ways to structure his fortune to save as much as £4bn in taxes, including possibly moving to Monaco. He’s certainly deploying his fortune in high-profile ways.

His chemicals company, Ineos, is spending millions sponsoring a professional cycling team, and, last week, the billionaire said he hasn’t abandoned his pursuit of Chelsea soccer club.

Meanwhile, the world’s wealthy are increasingly on the move. 108,000 millionaires migrated across borders last year, a 14% increase from the prior year, and more than double the level in 2013, according to Johannesburg-based New World Wealth.

Australia, the US, and Canada are the top destinations, according to the research firm, while China and Russia are the biggest losers.

3,000 millionaires departed the UK last year, with Brexit and taxation cited as possible reasons.

“It can be a sign of bad things to come, as high-net-worth individuals are often the first people to leave — they have the means to leave, unlike middle-class citizens,” said Andrew Amoils, at New World Wealth.

- Bloomberg