As investors swung from nervousness to confidence and back again the safe-haven euro rallied and dipped and rallied again. The first swing related to the US presidential candidate's debate, which Donald Trump entered in the lead and came out of in second place. Another was OPEC's unexpected decision to cap production, which pushed up oil and equity prices as investors embraced risk. Then came the story of Deutsche Bank, which might or might not be in trouble as the result of a $14bn fine in the States which would account for half its market capitalisation. That made investors nervous again.

Overall the euro did not move far against the US dollar. It added a couple of dozen ticks having covered a range of just one US cent. The euro took nearly a cent off sterling, which suffered from another week of Brexit uncertainty.