The 28-year-old hospital orderly was one of many across Switzerland rushing to cash in on a soaring Swiss franc.

Minutes after a shock announcement from the Swiss central bank that it was abandoning the minimum rate of 1.20 francs against the euro, the safe haven Swiss currency strengthened almost 30 percent to 0.8517 against the common European currency before easing back to 1.0421.

"I heard the news this morning. I'm so happy!" Vanessa, who refused to give her last name, told AFP outside of one of many mobbed exchange offices in Geneva.

She has reason to be extatic: she is one of some 280,000 people working in Switzerland but living and paying bills in eurozone countries France, Germany or Italy.

These so-called "frontaliers", or border-crossers, are the biggest winners in Thursday's Swiss franc surge, seeing their incomes jump 30 percent in the blink of an eye.

Vanessa said she was contemplating "changing all of my Swiss franc savings into euros".

Other frontaliers were also celebrating Thursday, but said they would not immediately buy large amounts of euros.

- Panic buying? -

"For those of us living in France and working in Switzerland, this is great!" said Doina Bancila, a 40-year-old bank employee.