He has arguably the toughest act in Corporate America—following Warren Buffett. But now that Greg Abel officially has a timetable to take over Berkshire Hathaway by year-end, the question is: How will he run it?

When Warren Buffett announced at his annual shareholder meeting that he is stepping down as CEO of Berkshire Hathaway at the end of the year, he elevated a 62-year-old Canadian executive named Greg Abel who has long been one of his top lieutenants.

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.