Wall Street leaders are now sounding alarms after a market sell-off erased trillions in value. Billionaire investor Bill Ackman warned of “a self-induced, economic nuclear winter” unless Trump pauses the sweeping tariffs for negotiations. JPMorgan’s Jamie Dimon echoed worry about long-term trade alliances in his annual letter. Financial executives reportedly raised concerns with Trump’s top advisers. Traders were stunned by the tariffs’ breadth, and while some analysts hold out hope for trade deals, others say the administration appears unfazed by market losses.