While Morningstar, Inc. (NASDAQ: MORN), the mutual fund and exchange-traded fund (ETF) rating agency, is highly regarded for its investment research, that doesn't necessarily mean its ratings are always the most accurate. Most investors are not experts, so they rely on third-party ratings to compare and contrast possible investments for their retirement portfolios, none more so than Morningstar.

 

Even the Financial Industry Regulatory Authority (FINRA) mutual fund analyzer relies on Morningstar. But the system is not infallible, and investors can get carried away by the simple, intuitive five-star Morningstar rating system.

 

These warnings are well heeded. It turns out a majority of highly rated funds in 2004 did not score so highly in 2014. Many mutual fund investors have horizons well beyond 10 years, so staying power matters. Even more intriguing, the lowest-rated funds may produce the greatest excess returns when compared to their style benchmarks.

Morningstar is a highly regarded mutual fund and exchange-traded fund (ETF) rating agency.

  • The agency's research is used by many big names in the financial sector, including the Financial Industry Regulatory Authority.
  • A study performed by Vanguard found that Morningstar's ratings were not a good method to predict performance when measured against a benchmark.
  • Morningstar itself acknowledges its rating system as a quantitative measure of a fund's past performance that is not intended to accurately predict future performance.

How the System Works

Conceptually, there are plenty of holes in the Morningstar method. If you boil it all down, the Morningstar star system is entirely dependent on average past returns. This means the system cannot account for outliers, such as when fund managers have one abnormally good or bad year to fudge their trailing average performances. Even worse, the star system cannot tell you if the fund had consistent leadership or if new managers arrived every two years.

 

Morningstar assigns a one- to five-star ranking to each mutual fund or ETF on a peer-adjusted basis. Every single metric is relative and risk-adjusted. Peer adjustment is achieved by grouping funds with similar assets together and comparing their performances. By "risk-adjusted," this means all performances are measured against the level of risk a manager assumed to generate fund returns.

 

The top 10% of funds in a certain category are awarded five stars. The next 22.5% receive four stars, the middle 35% get three stars, the next 22.5% get two stars, and the final 10% get one star. Every mutual fund wants to receive and boast about a higher rating, and Morningstar often charges a fee for the right to advertise its scores.1

 

Naturally, investors prefer to have their money in five-star funds and not in one- or two-star funds. It is for this reason that many rely heavily on Morningstar's evaluations when making investment decisions. There is a glaring flaw with this approach; by the time the fund receives a five-star rating for past performances, it might be too late to participate. In effect, Morningstar, and its dedicated followers, often show up late to the party.                                           
 In 2014, The Wall Street Journal requested that Morningstar produce a comprehensive list of five-star funds over 10 years starting in 2004. The publication discovered that 37% of funds lost one star, 31% lost two stars, 14% lost three stars, and 3% dropped down to one star. Only 14%, or 58 out of 403, retained their premium ratings.

 To express it a different way, investors invest money in a five-star mutual fund in the hopes of achieving five-star results moving forward, yet only 14% of such funds proved worthy of those hopes. If an investor was willing to accept a four- or five-star performance, the results were more palatable, since 51% of Morningstar's five-star funds in 2004 received a four-star or above rating in 2014.

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Given the turmoil of 2007-2009, there may be some recession-created distortions in The Wall Street Journal's decade-long performance report. However, recessions tend to occur more than once every 10 years (1.6 per decade since the 1960s), so it is rare for a decade without a downturn interrupting mutual fund performancesow-cost fund provider Vanguard ran an analysis in 2013 to see how Morningstar-rated funds performed relative to a style benchmark over three-year periods. The goal was to identify excess returns compared to the benchmark, and group those returns by star rating.

 

The Vanguard study produced two critical findings, the first being "an investor had a less than a 50-50 shot of picking a fund that would outperform regardless of its rating at the time of selection."3 This is different than saying five-star funds tend to outperform one-star funds in each category, which is generally true. What it means is that star rating is not a good method to predict performance when measured against a benchmark.