Asian shares fall on tech nerves as oil prices slip

Asia's stock markets fell on Tuesday amid tech sector concerns and falling oil prices following US threats of sanctions against Iran that turned out to be a bluff. US Treasury yields retreated from recent highs as reports emerged that the Treasury Department might use its cash account to help finance debt buybacks, potentially reducing the need for additional short-term bill sales.

Analysts are awaiting Nvidia's earnings report on Wednesday, which will be crucial in determining whether the chipmaker can meet high expectations. MSCI's Asia-Pacific index outside Japan dropped 0.5%, while Japan's Nikkei and South Korea's Kospi declined 0.9% and 2.7%, respectively. Alibaba's discounted US$10.2 billion share sale to fuel AI initiatives and Samsung Electronics' shareholder-return plan also contributed to tech sector pessimism.

The US dollar strengthened against the Canadian and British pounds following the administration's sanctions announcement, which prompted concerns about potential dollar hoarding by some countries and banks. Market participants are looking ahead to Federal Reserve Chair Kevin Warsh's upcoming speech in Jackson Hole, Wyoming, where clarity on future US interest rate policy is expected. Gold prices edged up 0.5% at US$4,675.51 an ounce.