The economic crisis in Spain has not just led to massive recapitalisation of the country’s banking sector, but has also set the bank’s stocks dwindling and, with them, their bosses’ fortunes.

Wealth-X, the Singapore-based wealth intelligence firm, has said that the heads of the two largest Spanish banks – Banco Santander and Banco Bilbao Vizcaya Argentaria – have lost a fifth of their net worth on average in the past 45 days.

Last weekend, Spain became the fourth eurozone country to receive outside assistance to stay afloat. The €100 billion ($125.5 billion) “bail-out” will be directed towards the country’s ailing banking sector. Investors have remained cautious, however, and Spanish 10-year bond yields almost stand at 7 per cent at the time of publication – the highest since the country joined the euro in 1999.

Emilio Botin, chairman of Santander, has taken the biggest hit and his fortune has tumbled from $1.5 billion to $890 million since the crisis started.

Santander’s chief executive, Alfredo Saenz Abad, has lost $10 million and is now worth $110 million.

Francisco Gonzalez, chairman and CEO of BBVA, has lost $5 million and he is now worth $55 million.

Santander’s private banking division employs around 2,000 people across 120 branches in Europe, Latin America and the US.

BBVA has private banking activities in Spain, Switzerland, the US, Mexico, Turkey (through its stake in Garanti) and China.

“Spain’s call for assistance for its banking sector may offer markets short-term support, yet the details are uncertain,” said Bill O'Neill, chief investment officer for Europe, Middle East and Africa at Merrill Lynch Wealth Management. “Spain has, to date, not convinced markets around the separation of the sovereign and banking sectors and the success of the programme in this regard is essential. It appears necessary for this to be achieved in the near-term.”

“While on the face of it, the deal would appear something of a triumph for Spain’s politicians - being able to negotiate funds without the shackles of the Troika inspectors and the significant conditions which had accompanied other countries; the implications of such favourable terms are likely to be for leaders in Dublin and Lisbon to squirm, and potentially to strengthen the calls in Athens for a renegotiation,” said Andrew Morris, managing director of Signature, part of UK wealth manager Rowan Dartington.

“Importantly, the borrowed funds still go through the government…potentially adding in the order of 10 per cent to outstanding nation’s debt,” Morris said. “This is far from ideal; the link between banks and sovereigns remains a fundamental weakness and a source of continued market uncertainty. We are left with the situation where governments and, by definition, EU taxpayers are on the hook for this money.

"Should events deteriorate from here or should the banking system review reveal further skeletons the situation gets much worse," Morris said. "As things stand, Spain and therefore Europe would be exposed to further liabilities. Unfortunately, estimates are already coming in putting the scale of the Spanish banking shortfall at between €400 billion and €500 billion.”