On April 2, President Donald Trump unveiled his "Liberation Day" tariffs, which included a 10% tax on most imported goods and heavier country-specific duties dubbed reciprocal tariffs. The news stunned Wall Street. The S&P 500 (^GSPC 0.74%) declined 12% during the next five trading days, leaving the index 19% below the record high reached in February.Ahead of that tariff-driven market crash, Warren Buffett's Berkshire Hathaway made two interesting capital allocation decisions in the fourth quarter. Of cours ...