Broker Check

Time the market at your peril

December 02, 2022

Technology enables immediate access to everything wherever and whenever we want it. In many cases, such as staying in touch with friends and family, or learning about world events, that’s a good thing. However, when it comes to investing and money management, my fear is that faster and easier ways of investing will allow people to lose more money faster and easier.

As access to investing expands, it becomes even more important to adopt an investment plan that doesn’t try to actively pick stocks or time the market. The purpose of having an investment plan is so you can relax. So you don’t look at the market every day, stressing out and asking, “How’m I doing? How’m I doing?” Investors actively trading are not just potentially missing out on the expected return of the market—they’re stressed out, worrying about how the news alert they just received will impact their long-term financial health, and whether they can or should do anything about it.

I don’t blame people for this. The financial services industry has not done a good enough job educating investors that the best approach for their long-term financial well-being is to make a plan, implement it, and stick with it.

But it has done a great job selling index funds. Over the past decade, the percentage of the stock market that is passively held has grown considerably, with equity index funds representing 52% of the US equity fund market at the end of 2021.1 And yet some investors appear to be using index funds to pursue an active investment approach. For example, the largest S&P 500 ETF had the highest average daily trade volume of US-listed securities in 2021, at $31 billion.2 So instead of picking individual stocks, people seem to be acting like stock pickers when buying and selling index funds and ETFs.
Despite the overwhelming evidence and compelling story to the contrary. When economist Michael Jensen published his landmark 1968 paper, which showed that active stock pickers added no consistent value, other academics soon confirmed his insights. More than five decades and 50 years of data later, the theory still holds up. There are some stock pickers who experience success, but we don’t know how to identify them before the fact. We can’t separate skill from luck. Picking stocks is more like gambling than investing.

This academic research inspired the invention of the index fund, which allowed investors not only to buy the broad stock market, but also to track the performance of the manager and compare costs. I worked on one of the first index funds. When I co-founded Dimensional, we built strategies that were informed by indices but weren’t limited by the same mechanical constraints. So I accepted this research early on and built a company based on it. I still believe it 50 years later. My colleagues and I weren’t sure at the beginning that it would appeal to a lot of people, but it did.

I’m proud of the fact that we have always viewed marketing as a way to educate financial professionals and investors. In fact, we started by working with institutions and only expanded to individual investors by working with financial advisors who could help teach their clients how to think about the market and invest for the long term. We wanted to prevent people from making the mistake I still see too many people making.

But I fear it will only get worse. ETFs make it easier to trade. So do free platforms that allow people to trade on their phones. There seem to be as many ETFs as there are stocks that make up those ETFs. I really like ETFs. They are another chapter in this 50-year story of creating safer and better financial products for investors. Our firm has been using them to give financial professionals and investors more choice in how they access Dimensional Investing. But they are tools, and they have to be used effectively.

Which is why you may need an advisor more than ever—to help keep you from jumping from one thing to another. Our approach is to get you out of the game of worrying and guessing by having a plan that can provide peace of mind. It’s a sensible approach you can live with. Trust the financial advisor who trusts the market.

The financial industry has made great strides improving the investment options available, but we have more work to do helping investors with those options. There are great solutions right in front of people. As an industry, we need to do a better job of educating current and potential clients. How the bulk of our society lives out their later years depends on it.


  • 1Data sourced from Morningstar; funds of funds are excluded.
  • 2US dollars.


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David Booth, Dimensional Fund Advisors