Historical Mutual Fund Performance Charts Are Hard To Interpret

For humor, let's assume for a moment that historicalvaluation. The rate of change between the investment
ETF and mutual fund performance charts actually dofund's historical performance and the market index
have some useful information for individual investors.benchmark is what counts.
This might not actually be very funny to many fundA consistently superior ETF or mutual fund would have
investors who have been lured into lousy anda cumulative performance line that increasingly and
expensive investments because of historicalconsistently diverges from the benchmark index.
performance charts.Visually, the wedge between the two lines should just
It can be hard to see humor, when the securitieskeep widening. On the other hand, a widening wedge
industry siphons away your assets through highcould also describe the situation of an overly easy
management fees using the siren song of superiormarket index benchmark comparison and mediocre
historical performance charts. The cover-your-rearETF or mutual fund performance.
small legal print in the footnote of the performanceRarely do you see historical ETF or mutual fund
chart is actually right. Essentially, it says, "Don't count onperformance graphs with increasingly widening lines --
it." And, you should not.particularly since luck is a major factor and high
Interpreting rates of change from a cumulativeinvestment management fees and high trading costs
performance chart is a challenge for many people.tend to drag fund performance down relative to
Visually, cumulative historical ETF and mutual fundappropriate market index benchmarks. If, for example,
performance charts are just very difficult to interpret.the lines diverged quickly ten years ago and then they
Most people would only look at the most recent valuesmaintained a relatively constant gap thereafter, that
to see whether the fund's cumulative performance tocould mean that a very small and immature fund got
date is above or below the index.lucky and/or it had a riskier investment portfolio profile.
Well, of course, if you are being sold to or advertisedThen, money from performance chasing individual
to, then the most recent cumulative performance willinvestors flowed in, and the fund got much larger. If the
always be above the market index benchmark,gap between the lines on the chart does not
because of selectivity. Selectivity means that fundincreasingly widen, then this means that subsequent
companies select only their "winners" to promote. Thisperformance has just been mediocre. If the lines tend
is the easiest kind of fund to sell to naive individualto narrow that demonstrates subsequent inferior
investors -- you know, "good" funds with "better"performance. Cumulative performance could still be
performance.above the index due to a selectivity bias and/or an
However, an ETF or mutual fund's performanceeasy index benchmark, but the fund might really have
history that would truly exhibit investment managementbeen exhibiting mediocre or inferior performance for
skill (or just a sting of good luck) is the relative rate ofyears.
change in fund versus index benchmark asset