The price of investment success is constant vigilance.

Buying and holding for the long term assumes that one is willing to settle for whatever long-term average return is generated.

Buying and holding for the long term also assumes that one can successfully select a stock, or group of stocks, whose fundamentals will continue intact.

Technology is moving ever more rapidly and for most corporations the relevant competitive context has become worldwide, whether or not they wish it were so. These facts imply that selections of companies likely will not remain valid as long as they could in the past.

In a dynamic world, a static portfolio is by definition a fatally flawed strategy.

Bottom line:  One year's favourable and seemingly stable fundamentals are not a given that can be assumed in perpetuity, much as we might wish they could.  The price of investment success is constant vigilance.

The advice to buy and hold long term begs a critical question:  buy and hold what?