United States benchmark averages finished mixed on Monday (Tuesday AEST), as investors assessed fresh U.S. economic pressure on Iran and prepared for a busy week featuring Nvidia's earnings and key inflation data.
The Dow Jones Industrial Average rose 140.2 points, or 0.3%, to 53,417.2, while the S&P 500 fell 21.5 points, or 0.3%, to 7,652.9. The Nasdaq Composite declined 200.3 points, or 0.8%, to 25,980.2.
The Trump administration announced the possible expansion of sanctions against countries doing business with Iran as part of what it described as an "economic D-Day", although it stopped short of imposing new penalties.
Technology stocks came under pressure, with Nvidia falling 2.9%, Micron Technology down 5.8% and Broadcom losing 2.6%.
Meanwhile, concerns over rising U.S. government debt had pushed the 30-year Treasury yield to a 19-year high before the Treasury announced support measures last week.
The moves have increased attention on Federal Reserve Chair Kevin Warsh's speech at the Jackson Hole symposium on Friday, with investors looking for clues about policymakers' assessment of the Treasury's efforts to stabilise the bond market.
Nvidia's quarterly results will also be closely watched, with any indication of slowing growth potentially reigniting concerns about elevated technology valuations.
Markets will also focus on the Personal Consumption Expenditures (PCE) price index, the Federal Reserve's preferred inflation gauge, due on Wednesday (Thursday AEST).
Separately, U.S. President Donald Trump warned that tariffs on cars, trucks and automotive parts from Canada would rise to 50% from 1 January after trade negotiations broke down over the weekend.
Automakers Ford and General Motors fell 3.3% and 1.1%, respectively, while trucking company J.B. Hunt Transport declined 5.7%.
On the bond markets, 10-year and two-year Treasury yields fell 0.8% and 0.1%, respectively, to 4.7% and 4.238%.
