BERLIN (AFP) - European Central Bank chief Jean-Claude Trichet insisted Saturday that the euro was a credible currency but said tighter regulation was needed of banks, markets and govt policies. Its not the euro which is under threat but the fiscal policies of certain countries which must be taken in hand, he said in an interview published in the Frankfurter Allgemeine Zeitung daily. European finance ministers on Friday agreed to harden budget rules in a bid to rein in a galloping debt crisis as global stock markets and the euro recovered slightly after a disastrous week. Financial markets have been racked for days by worries over the possibility that some eurozone economies will no longer be in a position to repay debts and even that the eurozone itself could come apart because of the crisis. But Trichet said, Market movements are always a combination of investors moods and the influence of speculators like the hedge funds. He recalled that he was in favour of greater regulation of banks and speculative funds. In the financial sector in general, not just in the banks, certain behaviour has developed which are greatly at odds with the basic values of our democratic societies, he said. We need a change of values in the financial sector. European and US stocks recovered at the close of trading on Friday despite sharp falls earlier in the day and the euro also rose against the US dollar and the yen, boosted by German parliamentary approval of Berlins share of a trillion-dollar rescue package for debt-stricken eurozone countries. Several European states have racked up huge debts and deficits as a result of the global economic crisis and the current turmoil kicked in as more and more investors lost confidence in governments ability to repay these debts. Europe has come under heavy criticism for its handling of the debt crisis, with many analysts pointing to indecision and discord in Europes biggest economies and at the very heart of European policymaking.