In yesterday’s commentary I touched on Einstein’s insight into an aspect of human nature that can kill one’s odds of achieving long-term investment success:

“Human beings must have action; and they will make it if they cannot find it.”

In last Monday’s Wall Street Journal, Wesley Grey made the point beautifully. Here’s a snippet (HT Jeff Miller):

Imagine the following theoretical investment opportunity: Investors can invest in a fund that will beat the market by 5% a year over the next 10 years. Of course, there is the catch: The path to outperformance will involve a five-year stretch of poor relative performance.  “No problem,” you might think—buy and hold and ignore the short-term noise.

Easier said than done.

Consider Ken Heebner, who ran the CGM Focus Fund, a diversified mutual fund that gained 18% annually, and was Morningstar Inc.’s highest performer of the decade ending in 2009. The CGM Focus fund, in many respects, resembled the theoretical opportunity outlined above. But the story didn’t end there: The average investor in the fund lost 11% annually over the period.

What happened? The massive divergence in the fund’s performance and what the typical fund investor actually earned can be explained by the “behavioral return gap.”

The behavioral return gap works as follows: During periods of strong fund performance, investors pile in, but when fund performance is at its worst, short-sighted investors redeem in droves. Thus, despite a fund’s sound long-term process, the “dollar-weighted” returns, or returns actually achieved by investors in the fund, lag substantially.

In other words, fund managers can deliver a great long-term strategy, but investors can still lose.

Yep, those stretches of poor/flat performance can drive a person insane!