[jonjenk]

Setting aside whether dollar cost averaging into a low cost index mutual fund is a good or bad strategy, the author falls prey to a common investing fallacy. It is most evident in this sentence, "Over the long haul, you won’t lose."

Experienced investors will immediately recognize that there is always some probability you will lose money regardless of the perceived safety of the investment. An investment provides return in exchange for risk -- there is always risk -- understanding this fundamental truth about investing is the the most important thing an average investor can do regardless of what the market is doing.

While the proposed strategy will provide a rate of return slightly below the broad market over long time horizons it's no sure thing. This observation is especially poignant on a day when the Tokyo market index is at a 28 year low.

http://www.cnbc.com/id/47668274