Oil rises 7.8 percent after U.S. and Iran assert control over Strait of Hormuz

Oil prices rose after the United States and Iran each stated that the Strait of Hormuz is under its control. Brent crude, the international benchmark, increased 7.8 percent to $81.92 a barrel. Tanker traffic through the strait has stopped because of regional fighting, which has raised fuel prices worldwide.

President Donald Trump said he is reinstating a blockade on Iranian ships in the strait. He also called for a 20 percent payment on all cargo passing through the waterway to reimburse the United States for protection services. Brent crude remains below its recent wartime peak near $120 a barrel.

AI concerns The S&P 500 fell 0.7 percent on Wall Street.

The Dow Jones industrial average declined 121 points, or 0.2 percent, while the Nasdaq composite dropped 1.4 percent. Australian sharemarket futures pointed to a 0.1 percent decline at the open. Chip stocks led the decline. Micron Technology shares fell 4.9 percent after rising 243.1 percent earlier in the year.

Nvidia shares declined 3.2 percent. South Korea's Kospi index dropped 8.9 percent, with SK Hynix shares falling 15.4 percent. Taiwan Semiconductor Manufacturing Co. shares in Taiwan rose 1 percent after the company reported June revenue up nearly 68 percent from a year earlier.

Its U.S.-listed shares fell 2.3 percent.

Antitrust challenge to media merger Twelve states filed suit in California federal court to block Paramount Skydance's $110 billion bid for Warner Bros. Discovery. The complaint alleges the deal would reduce competition in film distribution and cable channel licensing.