US Treasury yields surged to their highest levels since February on Friday as traders complained that liquidity was worsening as the $29 trillion market slump deepened. The yield on the 10-year Treasury climbed 0.19 per cent to 4.58 per cent. Treasuries, traditionally seen as the ultimate safe haven for the global financial system, are sinking deeper into the doldrums. Yields were below 3.9 per cent earlier in the week but Mr. Trump's erratic tariff policies have shaken investor confidence in US policymaking and the economy, triggering a flight from US assets. "If you're a foreign holder, there's real pressure to sell Treasuries and corporate bonds around the world," said Peter Tchir, head of US macro strategy at Academy Securities. "The real concern around the world is that they don't know what Trump is going to do." Friday's sell-off led to the worst week for Treasuries since 2019, while accompanying a fall in the dollar, according to Bloomberg Treasury Index returns. "We're concerned because what you're seeing shows that this is not a normal sell-off," said an executive at a European bank's bulk services division. "They show a complete loss of confidence in the world's strongest bond market."