Pau Barrena / AFP via Getty Images) AMD's shares are among the S&P 500's top gainers Wednesday. Key Takeaways Wednesday has been a good day for chip stocks so far, with an index of semiconductor shares recently up more than 2%. One reason for the rise: sustained optimism about spending on the buildout of AI capabilities, even in the face of "bubble" worries. Chip stocks are hot. Semiconductor shares are rising Wednesday, lifted by Advanced Micro Devices (AMD) which, with a recent gain of about 8%, ...