While many investors poured into the stock market last year, legendary investor Warren Buffett eased on the brakes. Berkshire Hathaway, the investment company Buffett founded and still leads,

The US government has sued a unit of Warren Buffett’s Berkshire Hathaway, accusing it of pushing borrowers into unaffordable loans—so customers would buy homes from the company’s manufactured housing business.

With Berkshire Hathaway delivering an average annual return of around 19.8% over almost six decades, Buffett clearly knows what he's doing. Unsurprisingly, he hasn't diversified Berkshire's holdings as much as most investors would.