Long term borrowing costs for the United States reached a multi decade peak on Thursday as investors accelerated a worldwide selloff of government bonds. The yield on the US 30 year Treasury note climbed to 5.44%, the highest level since June 2004, while the 10 year note touched 5.13% during the decline. A similar trend hit Asia, where Japan's 10 year government bond yield rose to its highest since 1996.

The current rally in yields marks a gain of nearly 500 basis points for the 30 year security from its 2020 low. Markets are reacting to concerns over the sheer scale of government debt as the selloff deepened following the reopening of Japanese markets after a holiday, according to analyst Anna MacDonald of Hargreaves Lansdown.