During periods of significant volatility in the capital markets, investors can lose patience and/or perspective and draw the conclusion that long term risk/return dynamics no longer apply because somehow “it’s different this time.”

I’ve been in this business for over 25 years, and time and again I have seen investors come to this conclusion, making big portfolio shifts because of it, only to regret these decisions later.

I vividly recall conversations with folks in the 1980s who insisted that Asian stock funds should constitute the bulk of one’s portfolio since America was in decline and Asia was rising. In the1990s, it often was very difficult to have meaningful conversations about asset allocation and thorough diversification when so many genuinely felt that all they needed was a few technology stocks or technology stock funds. In 2008 and early 2009, few had the stomach to trim their nicely performing government bond funds and add to their stock funds during the worst stock market environment since 1932.

In each of these examples, the phrase ‘it’s different this time’ crept into many conversations. Obviously, none of the above decisions worked out well.

At Merriman, we’ve always maintained the portion of clients’ accounts invested in stocks at 50% US and 50% foreign. This has served our clients well for many years. We invest this way because the US represents less than 50% of the world stock market capitalization, and because maintaining this kind of allocation can serve to increase returns while lowering overall portfolio risk.

Lately, foreign stocks have been significantly underperforming US stocks, and this has been causing some people to ask if maintaining our desired 50/50 US/foreign split still makes sense. And once again, we are starting to hear the ‘it’s different this time’ comment again. It is human nature to think this way, but history would suggest that one should not make a big shift in allocation because of it, other than some routine portfolio rebalancing.

Keep this in mind: While it’s always a different set of circumstances driving the capital markets, rarely is it wise to conclude that a paradigm shift is at hand and make major portfolio shifts in response. As legendary investor Sir John Templeton used to say, “The four most dangerous words in investing are ‘it’s different this time.’”