Stocks were up in January, which is usually a good sign for the year. But new tariffs could change that. - MarketWatch

1. U.S. stocks rebounded in January, indicating positive trends for 2025. 2. Tariffs imposed by Trump could significantly impact U.S. economy. 3. Nvidia lost nearly $600 billion in market cap, marking a record decline. 4. January Barometer suggests January performance predicts annual returns. 5. Federal Reserve's interest rate pause adds to market uncertainty.