We’ve often said that watching the market every day has little (if any) benefit to you as a long-term investor. However, we can’t help but hear or read headlines such as “Dow rallies 500 points” or “Dow drops 500 points.” These types of stock movement headlines may make little sense to some investors, given that a “point” for the Dow and what it means to an individual’s portfolio may be unclear. Also, events such as a 500-point move do not have the same impact on performance as they used to. With this in mind, let’s take a look at what a point move in the Dow means and the impact it may have on an investment portfolio.
Impact of Index Construction
The Dow Jones Industrial Average was first calculated in 1896 and currently consists of 30 large cap US stocks. The Dow is a “price-weighted” index, which is different than more common “market capitalization-weighted” (which is simply a product of its stock price and shares outstanding) indices.
An example may help put this difference in methodology in perspective. Consider two companies that have a total market capitalization of $1,000. Company A has 1,000 shares outstanding that trade at $1 each, and Company B has 100 shares outstanding that trade at $10 each. In a market capitalization-weighted index, both companies would have the same weight since their total market caps are the same. However, in a price-weighted index, Company B would have a larger weight due to its higher stock price. This means that changes in Company B’s stock would be more impactful to a price-weighted index than they would be to a market cap-weighted index. > SEE MORE