Published by Jamie JemmesonBond traders are increasingly mindful of former Federal Reserve chief Alan Greenspan's warning that higher bond yields are the "canary in the mine".Speaking to Bloomberg Television, Mr Greenspan warned that higher yields on government bonds will push up borrowing costs and potentially put the brakes on economic recovery.Following his comments, a Bloomberg survey of 18 primary dealers revealed expectations that bond rates for ten-year notes will hit 4.2 per cent this year, its highest level since October 2008.Bill Gross, manager of the world's biggest bond fund at Pacific Investment Management Co, said that bonds "have seen their best days"."The rally in treasuries is over," added James Caron, head of US interest-rate strategy at Morgan Stanley in New York.Currency risk management strategists may also benefit from paying close attention to a statement from Treasury secretary Tim Geithner due to be made at a symposium in Washington later today.For more information on foreign exchange treasury services and risk management, visit our Corporate FX site