The pound depreciated the most in more than four years against the dollar in the past week, amid speculation the Bank of England was moving toward higher interest rates more slowly than the Federal Reserve.

Bond markets are again being plagued by a drop in trading. While traders are returning from holidays and being less active than usual, prices are swinging. Yields on sovereign debt globally have plunged to the lowest ever, with rates on 30-year treasuries falling to their lowest point in more than two years.