Warren Buffett (Trades, Portfolio) is famous for avoiding exposing capital to technology companies. His basis for this is that he won't invest in anything he can't understand.
It is hard to imagine someone as smart as Buffett not being able to understand something, but it is his discipline that really sets him apart.
Bill Ackman (Trades, Portfolio) agrees with Buffett. Ackman's reasoning is that for a concentrated investor like him, technology businesses just change too fast, which makes it very difficult to assess long term durability.
