The Swiss Central Bank’s foreign currency reserves reached a record high in July as the country’s central bank bought tens of billions of euros to keep the franc weak.

The Swiss National Bank’s cash pile surged 11.3 per cent in the month to 406.5 billion francs. That pushed holdings to 71 percent of gross domestic product.

The SNB has had a policy of keeping the franc at a ceiling against the euro of CHF1.20 since September and has vowed to buy as many euros as necessary to prevent the franc from strengthening beyond that level.