Philipp Hildebrand, the chairman of the Swiss National Bank, resigned on Monday over a foreign exchange trading scandal involving his wife, Kashya.
Hildebrand resigned on Monday morning, saying in a press conference that he thought he had been "a damn good central banker".
Mrs Hildebrand, a former foreign exchange trader, admitted taking advantage of the weak dollar by buying $500,000 on August 15. She then played the other side of the currency movements, selling the dollars back into Swiss francs in October, according to the Financial Times.
In the interim, the SNB had taken drastic action to try to stem the rising franc, which is seen as a safe haven from the eurozone woes. The currency's rise was putting pressure on the country's exporters, who were seeing their margins squeezed.
On 9 September, the bank began to buy back francs, a dramatic and risky move that exposed the country to significant trading losses, as investors took advantage of the currency's sudden relative weakness to keep on buying.
The move's effectiveness has been questioned, but at the time many economists and analysts noted that, although desperate, it was necessary to rescue the country's economy. Japan, whose currency is also seen as a safe haven, took similar action shortly afterwards to stem the appreciation of the yen.
However, the fact that the Hildebrands have been seen to directly profit from the SNB's currency intervention turned the issue into a scandal, with the chairman facing increasing pressure to resign, despite his insistence that he had no knowledge of his wife's dealings.
The release of the information came via the Swiss People's Party, or SVP, which has been a leading critic of Hildebrand, suggesting that the leak was politically motivated. The bank itself cleared him of wrongdoing in December. However, with the credibility of the institution central to its role, his position increasingly looked untenable.