Warren Buffett hasn't turned his reputation as the world's best investor by accident.
Since the early 1950s, he has been buying and selling securities. First, for the investment partnerships he set up for family and friends and then on behalf of Berkshire Hathaway, which he took control of in the late 1960s.
Even though he has tried to cultivate a reputation of being a long-term investor, Buffett has been relatively active in buying and selling stocks. He's always held a few core positions in his portfolio, which rarely change, but the smaller positions do change frequently.
A study published nearly a decade ago concluded that the Oracle of Omaha had traded several thousand stocks during his term as the portfolio manager at Berkshire.
However,...

