US stocks mixed, Philly semi index rallies; August job openings fall 256,000

U.S. stocks were mixed on September 29, with the Philadelphia Semiconductor Index rallying 1.53%, while August JOLTS job openings fell by 256,000 to 7.079 million, below market expectations. Taiwan stock futures surged 644 points in overnight trading. The labor market data showed continued cooling, with hiring at 5.2 million and quits steady at 3.1 million, though layoffs did not sharply deteriorate. Tech news included OpenAI delaying its GPT-6.1 Astra model over safety concerns and Nvidia approving a $150 billion stock buyback. The Dow fell 0.63%, the S&P 500 dropped 0.31%, and the Nasdaq declined 0.20%. Nvidia rose 0.53%, while TSMC ADR gained 0.88%. Reports also suggested TSMC may build a second U.S. plant in Texas.