Stock market today: Tariff whiplash and drops in AI stars set off another pullback on Wall Street Wall Street's sell-off kicked back into gear on Thursday, and a U.S. stock market rattled by the whiplash created by President Donald Trump's tariffs and uncertainty about the economy fell sharply. Wall Street's sell-off kicked back into gear on Thursday, and a U.S. stock market rattled by the whiplash created by President Donald Trump's tariffs and uncertainty about the economy fell sharply. Wall Street's sell-off kicked back into gear on Thursday, and a U.S. stock market rattled by the whiplash created by President…