Class B shares of Berkshire Hathaway were designed to make the stock more accessible to retail investors.After roughly six decades, legendary investor Warren Buffett is no longer chief executive officer of Berkshire Hathaway (BRK.A 1.42%)(BRK.B 1.24%). During his long tenure, Berkshire's stock crushed the broader benchmark S&P 500 index, and Buffett became known as arguably the greatest investor of all time. Buffett will remain chairman of the company's board, but it's undoubtedly a new era at Berkshire.Buf ...