According to those that know Buffett the best, the key to his success is “rationality”.
Charlie Munger, vice-chairman of Berkshire Hathaway and Buffett’s intellectual partner for almost 50 years, has said that Buffett’s “brain is a superbly rational mechanism”.
Buffett's friend and Fortune author Carol Loomis concurs, she has said that “rationality is the single most important trait in his investment success”.
Roger Lowenstein, author of Buffett: The Making of an American Capitalist, wrote, “Buffett’s genius is largely a genius of character— of patience, discipline and rationality.”
Another Buffett author discusses how being rational is a crucial part of investment success below: