Markets worldwide experienced a decline due to a downturn in AI stocks. The S&P 500 fell, despite most of its component stocks rising.

The Nasdaq composite and Dow Jones Industrial Average also dropped, with the latter falling 130 points. This decline began in Asia, where Samsung Electronics' stock tumbled, even after the company reported strong preliminary numbers for the second quarter.

Further details on the market decline and Samsung Electronics' performance are available from the source. The downturn in AI stocks appears to have had a significant impact on global markets, but specific effects on local markets are not specified in the available information.