Investment Insights: Past Performance

A few weeks ago I wrote about the fact that, in the world of investing, past performance does not predict future returns. As a followup to this, I wanted to share a set of quotes relating to this topic that I ran across in The Bogleheads’ Guide to Investing

“There is simply no way under the sun to forecast a fund’s future return based on its past record.”

John Bogle, Founder of The Vanguard Group

“Top performance lists are dangerous.”

American Association of Individual Investors

“For the 20 years from 1970 to 1989, the best performing stock assets were Japanese stocks, U.S. small stocks, and gold stocks. These turned out to be the worst performing assets over the next decade.”

William Bernstein, Author of The Four Pillars of Investing

“Fund rankings are meaningless when based on past performance, as most are.”

Jack Brennan, CEO of Vanguard

“Buying funds based purely on their past performance is one of the stupidest things an investor can do.”

Jason Zweig, Money Magazine

If you liked these quotes, be sure to check out “Investment Insights: Timing the Stock Market” and “Investment Insights: Staying the Course.”

7 Responses to “Investment Insights: Past Performance”

  1. Anonymous

    People who are looking for some iron-clad insurance of a stock’s future performance are bound to be disappointed at some point… past performance is only one of the things people look at to lead them to a decision, as MITbeta points out, and it oughtn’t be the major one! The information available about a company might be enough to choke a horse, but at least you don’t have to rely on another person’s (sometimes tainted) opinions.

  2. Anonymous


    Actually, for every stock out there, there are reams and reams of data available about the company: quarterly reports, etc. Unfortunately, even professional analysts working for major brokerage houses do not have a very good track record of deducing what how any particular company will fare over the next period of time, mainly because the ultimate fate is driven by events that do not show up in such data and reports.

    Therefore it is unwise and imprudent to invest in individual stocks or managed mutual funds.

  3. Anonymous

    Cute. You can add David Hume’s Induction fallacy to those. Just because the sun rose yesterday does not mean it will again today.

    Unfortuneatly we have little other data available.



  4. Anonymous


    Why not? Because investing in individual stocks is a losing proposition unless you can buy nearly all stocks, in which case an index fund would be a lot easier to work with.

    Buying individual stocks will cost a lot in transaction fees, and nobody has yet found a reliable, repeatable formula for beating the market indices over the long run.

  5. Anonymous

    Jason Zweig, Money Magazine, uses TOO MANY WORDS:

    “Buying [managed] funds … is one of the stupidest things an investor can do.”

    In order to ‘pick’ a fund, you need to do as much analysis to ‘pick’ a stock … so why not invest directly in the stock, in the first place (and avoid the fund manager’s mark-up)?

  6. Anonymous

    Sounds like shorting the “best performers” could be a great strategy! The cover of this week’s Businessweek could be a treasure chest of potential shorts.

  7. Anonymous

    This is one of the things I cringe at when listening to Dave Ramsey. When he talks to people about investing, he says nothing about asset classes (besides “growth, growth and income, aggressive growth, and international,” which aren’t really asset classes) but simply talks about “track record.” Dave is has a great method for getting out of debt, but I’m afraid some people are going to be surprised with their investments after taking his advice.

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