It’s hard to escape the sense that something shifted in global markets this week. Consider the following list:

• Kamala Harris injecting new energy into the White House race.
• China’s increasingly desperate policymakers delivering a surprise rate cut.
• A string of profit warnings from global giants including Nestle, Nissan and luxury icon LVMH.
• Warnings from Australian regulators that the private credit boom is too opaque.
• Growing noise about the need to cut rates to support a slowing US economy.
• Sharp falls in commodity prices, particularly copper, the long-standing economic barometer.
• A sudden surge in the yen, which has hit carry trade bets across credit and equity markets.
• Signs the yield curve may be about to disinvert, which almost always happens just before a recession. Former Federal Reserve official Bill Dudley also called on the central bank to cut interest rates as soon as next week due to signs the US economy is cracking.
• A jump in the VIX volatility index.
• And, perhaps most worryingly, a sharp reversal in the seemingly bulletproof belief that artificial intelligence could keep the long bull market running.