Berkshire Hathaway 's (NYSE: BRK.A) (NYSE: BRK.B) stock has risen more than 50% over the past three years as the S&P 500 rallied less than 30%. That continued Berkshire's long tradition of beating the S&P 500 over the past four decades.

Berkshire Hathaway's share price hit a record high on Monday, reflecting investors' confidence in Warren Buffett's company, which is often regarded as a microcosm of the broader American economy.

Shares in Warren Buffett's Berkshire Hathaway (BRK.A, BRK.B) closed at a record high on Monday, buoyed by gains in some of the conglomerate’s key holdings, including Apple (AAPL), American Express, (AXP),