South Korean stocks extended their steep decline on Thursday, with the benchmark index tumbling as much as 8.2% (687 points), marking a second straight day of losses and taking the cumulative drop over the two sessions to 10%. The selloff gathered pace after Meta Platforms Inc.'s plans to sell computing power raised concerns about excess AI capacity, triggering a sharp fall in semiconductor stocks. Weakness in U.S. technology shares overnight further weighed on sentiment across Asian markets. In the U.S., chipmakers Micron Technology Inc. and Sandisk Corp. had both ended the previous session down more than 10%.