Larry Ellison, Elon Musk and Mark Zuckerberg: add up the net worth of the world’s three richest people, by Bloomberg or Forbes’ calculations, and you have roughly $1 trillion. That’s about equal to the market capitalization of Berkshire Hathaway, whose CEO Warren Buffett manages to get by with a mere$148 billion to his name. If the Federal Reserve cuts rates today, as expected, Buffett’s fundamentals-minded conglomerate is likely to face pressures distinct from the vanguard tech companies behind the weal ...