Building A Lifetime Portfolio

 | Jan 18, 2015 12:52AM ET

h2 How To Build a “Lifetime” Portfolio, Part I

This is the time of year when most investment writers predict what will happen in 2015. What I’d rather offer, however, is what is “most” likely to happen this year, next year, or the next 10, 20 or 50 years.

The short and glib answer is the one proffered by J.P. Morgan when asked what the market would do next. “It will fluctuate,” he replied. That may sound offhandedly dismissive of the question, but in fact there is much truth, and the beginnings of what we now call Modern Portfolio Theory (MPT) in his pithy response!

Modern Portfolio has much to recommend it and much to eschew. The basic idea is solid: MPT is a way to optimize your returns based on your acceptable level of market risk.

You accomplish this by diversification among various asset classes. If you can remember as far back as January 2014, almost every pundit was predicting a disastrous year for bonds, a so-so year for US stocks to digest the gains of 2013, and sector bets all over the place. I don’t know of a single analyst who predicted that the best-performing sector in the USA would be utilities, yet there they are, proudly atop all markets.

The matrix below shows what asset class performed best over the past few years. (These are asset classes, not business sectors, so you won’t see utilities there, but you will see “REITs” and both “High Grade” and “High Yield” bonds, both of which are equally-interest-rate-sensitive.) If you look carefully at every year, you will note the results vary considerably. The same holds true over all other, even more extended, periods. Diversification works! Yes, you will sometimes fail to beat the market, “market” being shorthand to most investors for the “Large Caps” represented by the S&P 500, but over most periods other than an out-and-out bull romp in US stocks that means you are likely to do much better.