Asian Markets Slide as Oil Spikes and OpenAI Pauses AI Training

Key points

• Asian indices dropped, with South Korea's KOSPI down 2.7% and China's CSI 300 falling 2.2%, while Hong Kong's Hang Seng bucked the trend by rising 0.6%.
• Brent crude climbed over 2% to above $107 per barrel after President Trump rejected an Iranian proposal to reopen the Strait of Hormuz, extending September's oil gains to over 19%.
• U.S. 30-year Treasury yields reached 5.5185%, near their highest since 2004, as markets priced in a 66% chance of a Federal Reserve rate hike in October.
• Chipmakers suffered significant losses, with SK Hynix and Samsung Electronics dropping nearly 5% each, following news that OpenAI paused training for some advanced AI models to strengthen safety controls.
• Investors are watching a data-heavy week, including U.S. inflation and labor reports, alongside developments regarding the Strait of Hormuz and the Reserve Bank of Australia's policy decision.

Background

This volatility follows a month of rising oil prices and bond yields, which previously pushed Brent crude above $100 and the 10-year yield near 5%. Earlier in September, markets had seen mixed signals, with tech stocks rallying despite inflation concerns, but recent geopolitical tensions have intensified pressure on global risk assets.

Why it matters

The simultaneous rise in oil prices and bond yields signals persistent inflationary pressures, potentially forcing central banks to maintain or increase interest rates. The OpenAI pause raises concerns about a slowdown in AI development, which could dampen demand for advanced chips and data-center infrastructure, impacting the broader tech sector.

What to watch

Markets will closely monitor U.S. inflation, manufacturing, and labor-market data this week. Additionally, the Reserve Bank of Australia's policy decision is expected to include a 25-basis-point rate hike, while ongoing negotiations regarding the Strait of Hormuz will continue to influence oil prices and global risk appetite.