America’s status as a safe haven and benchmark has been tarnished. To great surprise, the US ratings agency Standard & Poor's placed the country’s rating on negative outlook for the first time in 70 years. But despite markets being shaken up, any hope or fear of a revitalised rival to US Treasury bonds is still unlikely.

Back in April 2009, there had been much talk of countries moving away from Treasurys as a benchmark for pricing of other securities, and relying more heavily on SDRs - special drawing rights backed by the International Monetary Fund.