While the iPhone maker’s inclusion in the Dow Jones Industrial Average is long overdue, the change itself doesn’t really move the dial.

This morning, the Dow Jones Industrial Average finally got around to adding Apple. which means the most famous benchmark for U.S. stocks will now include the worlds most valuable and influential company.

As the largest corporation in the world and a leader in technology, Apple is the clear choice for the Dow Jones Industrial Average, said David Blitzer, managing director and chairman of the Index Committee at S&P Dow Jones Indices.

The official move is expected to take place on March 19, but Apple shares are already jumping on the news. The stock was up more than 1% Friday afternoon, on a day when the Dow itself was down more than 200 points at midday.

Before you get too excited, though, there are several things you ought to know about this move:

1. Apple wont get a meaningful long-term bounce from being in the Dow.

The Dow may be closely followed, but its not a market mover. Thats because while there are hundreds of index funds that track the S&P 500, there are only a handful of index funds that follow the Dow. And those funds and ETFs are tiny in comparison to the more than $5 trillion invested in S&P 500-linked portfolios.

The SPDR S&P 500 ETF, for instance, controls nearly $200 billion in assets, while its sister fund, the SPDR Dow Jones Industrial Average ETF, has only around $12 billion.

2. The Dow has a record of terrible timing when it comes to addingor deletingcompanies from its average.

Consider some of the recent moves:

In February 2008, Bank of America was added to the Dow in the midst of the mortgage crisis and global financial panic, while the tobacco giant Altria was removed. Since being kicked off the list, the defensive-oriented Altria has gained more than 139%, nearly tripling the gains for the S&P 500. Meanwhile Bank of America lost two third of its market value until it was eventually kicked out of the Dow in September 2013.

In April 2004, the insurance giant AIG was added to the Dow just a few years before the company had to be bailed out from collapse by the federal government in the global financial panic. Between then and September 2008, when AIG was removed from the Dow, the stock lost more than 90% of its value.

And then there was the classic case of being late to the party with tech. In November 1999, the Dow finally decided to add Microsoft and Intel after they both experienced astronomical runs throughout the 1990s. Since being included in the Dow, Microsoft shares are down 8% while Intel stock is 12% lower. All the while, the S&P 500 has gained ground:

All of this confirms a study by University of Pennsylvania finance professor Jeremy Siegel. He looked at the performance of companies that were added to and removed from the Dow between 1957 to 2006, and found that the companies deleted from the Dow tended to outperform the new additions.

3. The Dow is a strange index to begin with.

As MONEY pointed out last year, the Dow is really an antiquated benchmark. Traditional modern indexes are market-capitalization weighted. What that means is that the bigger a company is, based on its market value, the greater its influence on the index. Thats why Apple, as the most valuable company in the world, comprises nearly 4% of the S&P 500, versus around 2% for Exxon Mobil, which is the markets second biggest company.

By contrast, the Dow is a so-called price-weighted index. That means that the higher a companys share price isnot its overall value, but the arbitrary price of a single sharethe greater its sway.

Right now Visa, at around $272 a share, accounts for nearly 10% of the Dows movements. However, Visa announced it would split its stock in four, diminishing the value of each share but not the overall company.

Dow officials cited this as a reason for including Apple. They consider Visa a tech stock, since the company works in global payment technology. But because Visas meaningless stock split will nonetheless reduce the Dows exposure to tech, Dow officials felt the move will make room for Apple, Blitzer said.

4. The company that Apple is replacing is vital to Apples success.

Dont think the Dow is trying to make a statement about the importance of the smartphone revolution to the U.S. economy: To make room for Apple, Dow officials kicked out AT&T.

Yet the telecom giant has been a vital cog in the smartphone era, selling data plans, iPhones, Android devices, and other technology. AT&T has already begun marketing smart watches, which is important as Apple is scheduled to unveil its Apple Watch at an event on Monday.

5. Apple doesnt need the Dow to gain credibility.

Apple is by the far the most valuable company in the world. Just with its savings account (the cash it has on hand) the company could buy three companies that are already in the Dow outright DuPont, Caterpillar, and the Travelers Group.

Whats more, in the past two years, Apple shares have quadrupled the gains for the Dow. And since the end of 1999, Apple has soared more than 3,000% when the Dow is up barely 50%.

So you could say that the Dow needs Apple, not the other way around.