Stocks have dived and investors are scrambling to the safety of bonds, gold and the yen as US President Donald Trump unveiled a bigger-than-expected wall of tariffs around the world's largest economy, upending trade and supply chains. The high-flying tech sector was pummelled as manufacturing hubs in China and Taiwan faced new tariffs above 30 per cent, bringing the total new levy to an eye-watering 54 per cent on imports from China. "The US effective tariff rate on all imports looks to be the highest level in over a century," said Citi's global rates trading strategist Ben Wiltshire. Nasdaq futures...