How about that? Dow 20,000! What a hugely important milestone! Right? Well, not really.
Sure it will make for a good front page story in USA Today tomorrow, and those few humans who are still needed on the trading floor of the New York Stock Exchange (they've been largely replaced by machines) will unpack the Dow 20K hats for sure, but Dow 20,000 is no more important than Dow 18,763.
When the Dow Jones Industrial Average is this high, we actually would expect new milestones to be reached on a very regular basis. An average stock market year (+10%) would actually see us break through another 1,000 point level every six months. Even if we stretch the milestone interval to 5,000 points, it will only take two and a half years on average.
In fact, it only took 18 years from 10,000 to 20,000. That might sound like a long time for the index to double (it's only a 4% average return during that time), but that period includes the massive dot-com market collapse of 2000-2002, as well as the Great Recession of 2008-2009.
Here is a calendar breakdown of Dow Jones milestones:
As you can see, every milestone from Dow 3,000 through Dow 20,000 has occurred since the 1990's. Dow 1,000 --- now that was a milestone... it took 76 years from the index's creation in 1896 for it to pierce the 1,000 level!
Also of note is how the Dow itself has become less and less relevant over time for investors. Most of us use the S&P 500 index since it represents more broadly diversified group of public companies, versus just 30 for the Dow. This is also because the S&P 500 is value-weighted, meaning that a company worth $10 billion comprised twice as much of the index as a $5 billion company.
The Dow, on the other hand, is share price-weighted. So while Bank of America (market value $235 billion) is ~2.5 times larger than Goldman Sachs (market value ~$95 billion), it actually makes up far less of the Dow's composition than Goldman does. In fact, BofA's share price is only 1/10th that of Goldman, so a $1 increase in GS stock (which is a gain of 0.4%) adds the same amount of points to the Dow as a $1 increase in BofA stock (a gain of 4%) does. It's really a bizarre methodology.
Despite all of that, I'm glad we are getting 20K out of the way so we can stop hearing about it. That is, of course, until we hit Dow 25K, which history suggests is most likely to happen in just a few years.