A weak earnings preview from Samsung Electronics sent jitder through the semiconductor sector, with the South Korean firm's shares dropping nearly 7%. The company projected record operating profits but included a provision for employee bonuses, which investors interpreted as a negative signal for future earnings reports from chipmakers and AI-related technology firms. This sentiment contributed to a broader market downturn, with the Nasdaq Composite falling 1.2% and the S&P 500 declining 0.5%.

Other market movers included SpaceX, which slid almost 7% after its inclusion in the Nasdaq-100, despite analysts initiating coverage with high price targets. Meanwhile, oil prices surged more than 3% to over $74 a barrel after Iran's Islamic Revolutionary Guard Corps launched missiles near the Strait of Hormuz. This geopolitical event caused the largest one-day move in Brent crude since early June.

In corporate finance news, Amazon.com announced plans to issue at least $25 billion in bonds, its second major debt offering in months, while electric vehicle maker Rivian saw its shares tumble more than 18% on news it would sell 75 million shares to fund a new Georgia manufacturing plant. These events highlight investor caution around tech earnings and ongoing shifts in energy markets and the EV sector.