Concentrated Bets Over Diversified Dribbles

“Buffett believes that exceptional returns come from concentrated portfolios, that excellent investment ideas are rare, and he has repeatedly told students that their investing results would improve if at the beginning of their careers, they were handed a twenty-hole punch card representing the total number of investments they could make in their investing lifetimes.”

“Buffett’s pattern of investment at Berkshire has been similar to the pattern of underwriting at his insurance subsidiaries, with long periods of inactivity interspersed with occasional large investments. The top five positions in Berkshire’s portfolio have typically accounted for a remarkable 60–80 percent of total value. This compares with 10–20 percent for the typical mutual fund portfolio. On at least four occasions, Buffett invested over 15 percent of Berkshire’s book value in a single stock, and he once had 40 percent of the Buffett Partnership invested in American Express. The other distinguishing”