Wall Street tanks on growing uncertainty over Trump's tariffs, Fed battle
1. Trump's tariffs ruled unconstitutional, invoking market uncertainty. 2. S&P 500 dropped 0.97%, reflecting widespread sell-off in stocks. 3. September historically weak for S&P 500, average decline of 4.2%. 4. Federal Reserve's rate decision impacts market outlook. 5. Big Tech stocks saw significant declines amid trader rotations.