Other fund managers also hold major stakes in Berkshire Hathaway Class B shares. BlackRock owns nearly 111.6 million Class B shares, roughly 8.3% of the total outstanding shares. State Street Corporation ranks high on the list as well, with nearly 71.7 million Class B shares making up 5.35% of the total.

What to know about Warren Buffett, the billionaire stepping down from his role as chief executive at Berkshire Hathaway.

Abel was named vice chairman of Berkshire Hathaway in 2018. Although he has been at the company for more than two decades, he is considered to be much more guarded and hands-on than Buffett.