John Templeton had an uncanny ability to invest without getting emotional, as William Green’s January 1999 article in Money magazine describes:

When the U.S. market crashed in 1987, Templeton loaded up on stocks that had been slaughtered. “He doesn’t get carried away by the emotions of Wall Street,” says Jay Bradshaw, who ran Templeton’s trading desk. “He said, ‘Well, if we paid that much for Ford Motor before and it was good value then, it’s even better value now.'” This habit of diving in when stocks are getting crushed requires “Tremendous willpower and strength of personality,” says Mobius. “Everybody else is running out of the burning building.”

Templeton has always been just as immune to euphoria. In 1969, when the U.S. market was surging to breathtaking heights, he was massively underweighted in U.S. stocks. The bubble burst, and many stocks fell 70% between 1969 and 1974. In those terrifying years, his fund–largely invested in Japan and Canada–boasted a positive return of 50%.