AMD shares fall as analysts worry AI chip targets may be ambitious

The fall came amid a broader sell-off in the tech sector that saw megacap stocks fall 1.5% to 5% and the Philadelphia SE Semiconductor Index drop 3.5%. Wall Street fell on Wednesday after rating agency Fitch downgraded the U.S. government's credit rating. $Advanced Micro Devices (AMD.US)$ $PHLX Semiconductor Index (.SOX.US)$ $Direxion Daily Semiconductor Bull 3x Shares ETF (SOXL.US)$

AI has been a key theme in the chip sector so far this year, driving shares of chip companies and helping Nvidia $NVIDIA (NVDA.US)$ become the first and only semiconductor firm to be valued at more than a trillion dollars.