US Stocks Poised for Lower Open as Iran Tensions Escalate Oil Prices

US stocks are poised to open lower on Tuesday as escalating tensions between the US and Iran lift oil prices and push government bond yields to multi-year highs.

A senior Iranian official told Reuters that Iran would adopt a 'fully offensive' military posture due to stalled efforts to negotiate a permanent end to the war with the US. Washington has ruled out extending a temporary ceasefire agreement that expired on August 17.

The developments have pushed Brent crude futures up 0.3% and driven yields on long-term government bonds, including the 30-year Treasury bond, to their highest levels since 2007.

Kim Forrest, chief investment officer at Bokeh Capital Partners, noted that higher yields 'portend a tighter environment' and make borrowing money more expensive, particularly for tech companies with uncertain future profits. This has put heavyweight tech stocks under pressure, with Tesla, Nvidia, Micron Technology, Marvell Technology, Advanced Micro Devices, and Intel leading losses among growth stocks in premarket trading.