At another level, the breakup was a reminder of something else: the perils of personality-driven investing, a growing and lucrative business for the Wall Street bankers cranking out, rapid-fire, a never-ending array of new financial products.

Wall Street loves a catchy acronym, and the “TACO trade” has captured the mood, as investors and analysts attempt to make sense of the roller-coaster market action that has followed President Donald Trump’s sweeping tariff threats and subsequent walk-backs.

Wall Street's stock indexes ended lower on Thursday in choppy trade as a slump in Tesla shares offset news of progress in tariff talks between U.S. President Donald Trump and Chinese leader Xi Jinping.