Jim Cramer: Here's my advice for investors as stocks dive on Trump's tariffs

1. Cramer advises long-term investors to hold amidst market plunge. 2. Current P/E ratios for S&P 500 show a significant decline. 3. Historical financial crisis reflects potential recovery after downturn. 4. Investors need to time market entry carefully to avoid losses. 5. Cramer purchased stocks, indicating confidence in certain market segments.