Stock Market Today, Sept. 30: Nvidia Authorizes $150B Buyback, Lifting Total to $235B

Nvidia (NASDAQ:NVDA) , an AI chip and networking provider, closed at $228.38, up 0.51%. Premarket buyback headlines and a session update on its AI safety accord kept investors focused on capital returns and AI demand. Trading volume reached 117.7M shares, coming in nearly 5.2% below its three-month average of 124.1M shares. Nvidia IPO'd in 1999 and has grown 556,695% since going public. How the markets moved today The S&P 500 (SNPINDEX: ^GSPC) closed at 7,654, down 0.23%, while the Nasdaq Composite (NASDAQINDEX: ^IXIC) finished at 26,861, up 0.24%. Among semiconductor peers, Advanced Micro Devices (NASDAQ:AMD) closed at $611.76, up 0.69%, and Broadcom (NASDAQ:AVGO) closed at $351.19, down 1.