The richest people in the U.K. lost $5.5 billion Friday after the country stunned global markets by voting to leave the European Union. The drop for the 15 wealthiest Britons tracked by the Bloomberg Billionaires Index came as European markets headed for the biggest fall since 2008 and the sterling plunged to its lowest level in more than 30 years.

Peter Hargreaves, co-founder of Hargreaves Lansdown, the U.K.’s largest retail broker, supported the leave campaign and paid the price in the market reaction to the vote. His net worth tumbled 19 percent to $2.9 billion in mid-day trading, the largest percentage drop among the British billionaires.

Hargreaves said politicians who supported the remain cause should have nothing to do with process as the U.K. seeks to extricate itself from the EU.

“They may still keep their positions," he said in a telephone interview Friday. "But they cannot under any circumstances be involved in our relationship with the EU.”

The billionaire made the largest donation -- 3.2 million pounds ($4.4 million) -- to the leave campaign, according to filings with the U.K.’s Electoral Commission. After stepping down from the Hargreaves Lansdown board in April 2015, the billionaire said that he would welcome the chance to work with the U.K. Government as it prepares for a future as a non-EU member.

Both sides of the heated campaign over whether to leave or remain in the 28-nation bloc drew prominent billionaire backers. Inventor James Dyson and construction-equipment magnate Anthony Bamford were vocal advocates of Brexit while Richard Branson, Li Ka-shing and George Soros were among those urging to stay.

The country’s 15 richest citizens lost a collective $5.5 billion as of 3:30 p.m. in London, according to the Bloomberg index. Britain’s richest person, Gerald Grosvenor, led the decline with a loss of $1 billion, followed by Topshop owner Philip Green, fellow land baron Charles Cadogan and  Bruno Schroder, majority shareholder of money manager Schroders Plc.

Green lost almost $500 million and Schroder lost more than $600 million. Grosvenor and Cadogan, whose fortunes are derived mostly from London property, lost a combined $1.6 billion based solely on the drop in sterling.

Billionaire Reaction

Virgin Money Holdings Plc, the U.K.-listed finance business controlled by Richard Branson’s closely held Virgin Group Holdings, saw its shares fall by the most since November 2014. In a post on Virgin Group’s website in response to the referendum’s result, Branson said the decision to leave the EU will create volatility and cause damage to Britain’s economy, but stressed acceptance of the decision and the nation coming together.

“The U.K. and its amazing, resilient people have weathered many storms -- and with determination, resolve and sense of what is right,” Branson wrote in the post, which paid tribute to Labour Party MP Jo Cox, who was killed in her West Yorkshire constituency during the referendum campaign. “Those qualities will be needed over the testing months and years to come.”

South Africa’s richest person Christo Wiese, who owns U.K. assets including fashion retailer New Look and grocer Iceland, said his "preference was unguardedly for the U.K. to remain" and was surprised by the result.

"I don’t think it’s the end of the EU, I think it’s the end of EU as it’s currently structured," Wiese said in a telephone interview. "It’s always had unattractive features alongside it’s attractive features. This will make people sit up and say how can we make it better."

Wiese, whose bid for British discount retailer Poundland was rejected last week, said he had no plans to scale back his U.K. investments or change his strategy.

"We’re by and large at the value end of the business scale and that’s a very good place to be in Britain today."

Brexit Confidence

Hargreaves was unmoved by the negative market reaction. The billionaire said he was confident the decision is the best for Britain and made a bid to help the country shape its economic future.

"I have enormous experience of business, enormous experience of negotiation, enormous experience of economics, and I’m one of Britain’s most successful businessmen,” he said. "If they don’t involve me, they’re crazy."