Australian, Japanese and South Korean shares slumped. Equity-index futures for the S&P 500 and the tech-heavy Nasdaq 100 slipped in early Asian trading. Treasuries advanced while a gauge of the dollar slipped. mainland Chinese investors bought an unprecedented amount of Hong Kong stocks on Monday, continuing to boost their holdings amid a tech-driven rally this year. The latest turmoil on Wall Street marks an abrupt about-face for markets, where the dominant driver of the last few years had been the surprising resilience of the US economy even as growth weakened overseas. The dollar rose 0.2%. about 10 high-grade companies delayed US bond sales on Monday. Oil fell to a six-month low. The yield on 10-yearTreasuries slid nine basis points to 4.21% on Monday on bets that an economic slowdown would force the Federal Reserve to slash interest rates. In the megacap space, Tesla Inc. sank 15% while Nvidia Corp. drove a closely watched gauge of chipmakers to the lowest since April.