Index funds have long been marketed as one of the calmer corners of investing: instead of trying to guess which individual stocks will win, investors buy a slice of an entire market benchmark. But what happens when a company like SpaceX — an enormous wager and, in my view, wildly expensive — gets rushed into the Nasdaq-100? Could that kind of high-profile addition make Nasdaq-100 index funds more fragile? And could a $1.77 trillion IPO end up shaking the retirement accounts of everyday investors who never set out to own a piece of Elon Musk’s latest market spectacle?
The real answer is less about SpaceX itself than about the machinery behind index funds: how they are built, why they became so dominant, and why they are often considered a lower-risk way for ordinary people to participate in the stock market. To unpack that, I spoke with Burton Malkiel, one of the most influential figures in the history of index investing.
“If I were buying individual stocks, I would think twice about buying SpaceX, which is tremendously overhyped,” Malkiel told me. Still, he does not see SpaceX as a reason to abandon index funds. Understanding why requires a closer look at what index funds actually do, how a company like SpaceX fits into them, and what investors should expect when a blockbuster stock enters a major benchmark.
An index fund is designed to mirror a market benchmark, such as the S&P 500 or the Nasdaq-100, rather than trying to outperform it through stock picking. Malkiel helped bring the concept into the mainstream with his 1973 book A Random Walk Down Wall Street. The “random walk” idea is simple but powerful: a stock’s past price movements do not reliably tell investors where it will go next. Because the future is so difficult to forecast, consistently beating the broader market over many years is exceptionally hard. For most investors, the better bet may be to own the market and let its long-term growth do the work. As Malkiel put it to me, “A very small minority of stocks are responsible for the whole return, and experts can’t pick them any better than the index as a whole.”
That philosophy has attracted some famous supporters. Warren Buffett, for example, has said the typical investor would likely be best off putting 90 percent of their money into “a very low-cost S&P 500 index fund.”
Index funds and other passive investing strategies are no longer niche products, either. In 2024, assets managed through passive investment vehicles surpassed those in actively managed funds, according to Elise Ryan of State Street Investment Management.
Why are people worried about SpaceX specifically?
Just before SpaceX went public, Nasdaq adjusted the rules for the Nasdaq-100, allowing a newly listed company to enter the index as soon as its 15th trading day if it is large enough. That change was made at SpaceX’s request, Reuters reported.
Once SpaceX entered the Nasdaq-100 on July 7th, funds tracking the index were effectively required to buy the stock. Curiously, SpaceX shares had closed lower on July 6th. Part of that likely came down to market structure: traders knew index funds would have to purchase shares, giving banks and hedge funds room to position themselves around the forced buying. Index rebalancing funds, meanwhile, appeared to benefit handsomely. Finance remains endlessly interesting, and full of creatures with very sharp teeth.
There’s reason to believe that the index fund buying is part of the reason SpaceX had its initial IPO pop, according to research from Harvard Business School. What’s more, SpaceX is the initial entry into indexes for a number of expected mega-IPOs. Anthropic and OpenAI are expected to make their debuts later this year.
Also, people don’t like Elon Musk.
What does the index fund inclusion mean for SpaceX?
Some degree of price stability. New IPOs often fluctuate wildly. For instance, Facebook’s shares dropped 25 percent the Monday after its 2012 IPO, tripping breakers to halt trades.
Beyond the fluctuations from the market itself, a lot of people will soon be able to sell SpaceX shares that aren’t yet on the market. SpaceX employees are subjected to “lockup periods,” where they can’t immediately cash out and sell their stock following the IPO. Those periods are going to expire, and doubtless some people will want to sell shares. The index funds are likely to “help absorb some of the selling,” thus keeping the price from dipping too low, according to The Wall Street Journal.
How important is SpaceX in these index funds?
The company has a market cap of more than $1.5 trillion as of this writing, which is obviously enormous. But the IPO sold less than 5 percent of the company’s shares. Because of the way the Nasdaq adjusts its index, SpaceX will be treated like a much smaller company.
But remember, next month more SpaceX shares will be released from lockup. People with 180-day lockups can sell more shares than were initially sold in the IPO after SpaceX publishes its second quarter financial results, notes Bloomberg’s Matt Levine. Those results are expected in mid-August. That will make it more important in those index funds — though whether the price will fluctuate much is anyone’s guess, as short sellers are also anticipating the lockup releases. These market mechanics may explain some of the stock’s short-term price fluctuation, even though the company hasn’t had much major news occur.
SpaceX may take up more room in index funds as more shares are sold. But it might not, as selling usually drives down the price.
Why are people mad about SpaceX in index funds?
One big reason is the amount of power it puts in the hands of Musk. The CEO of CalPERS, an important retirement fund, and the New York state and city comptrollers sent SpaceX a nastygram about its “novel and extreme governance structure” — specifically, that only Musk decides what to do with the company and everyone else is along for the ride. Musk is temperamental, imperious, and prone to erratic behavior. That has consequences for shareholders of his companies, sometimes leading to enormous swings in value.
Musk has the majority of the voting rights for SpaceX. In other companies, shareholders can theoretically influence outcomes through shareholder proposals. With SpaceX that isn’t true. Other companies can be sued by shareholders for bad behavior, but SpaceX has limited shareholders’ litigation rights. One way to avoid a company that has made these choices is to sell the stock — but the inclusion in index funds means that’s harder.
Also, again, people don’t like Elon Musk.
But wait. I don’t vote on the corporate governance for companies in my index funds. Why does corporate governance matter to me?
You don’t, but the big indexers do. That means a lot of power is concentrated in just a few hands. It’s one of the worries people have about index funds. There are some other criticisms of index funds, too — that they buy high and sell low when they rebalance, for instance — and some investors believe they distort the market, making big companies even bigger. That’s why some analysts have called index funds “worse than Marxism.” Coming from capitalists, that’s a pretty big insult.
But still — if you believe those big indexers are sophisticated investors who are working on your behalf, you want them to make choices in corporate governance. To, for instance, vote against acquisitions that might be bad for shareholders, or install problematic members of the board of directors.
It seems like if you add up all these mega-IPOs along with the existing tech companies, there’s a lot of AI concentration in the index funds. Should I worry about that, in case AI is a bubble that pops?
Even before SpaceX entered the Nasdaq-100, most of its biggest companies were already AI-heavy — like Nvidia, Apple, Microsoft, Amazon, Google parent Alphabet, Broadcom, and Meta.
One of the biggest criticisms Malkiel hears about index funds is that the market is extremely concentrated, so that 10 companies are worth more than 30 percent of it. But he doesn’t view that as an argument against index funds. “The market’s always been concentrated,” he says.
“We’ve overhyped every technological change in history,” Malkiel adds. Railroads were overhyped, and so was the internet in the ’90s, and doubtless we are overhyping AI right now. That’s not a reason to be scared of index funds. “You’ve got to remember that it’s a very small minority of stocks that are responsible for all the return in the market,” Malkiel says. “That’s why you shouldn’t be terribly worried.”
What else are people worried about?
SpaceX isn’t getting fast-tracked by the S&P 500, another major index with its own governance rules. That may create significant differences in returns between index funds tracking the S&P 500 and the Nasdaq-100. (I, for one, look forward to seeing how that plays out.)
I suspect that most of the growth in SpaceX’s value has already been realized — which is why we have a megacap IPO in the first place, so that all the private investors can cash out — but as with Tesla, SpaceX is a meme stock with a sizable interest from retail investors. That decouples its performance from its fundamentals, effectively making it difficult to predict how the stock will actually do.
Does SpaceX’s size and inclusion suggest people should simply buy SpaceX stock directly?
No, says Malkiel. “If I were buying individual stocks, I would think twice about buying SpaceX, which is tremendously overhyped,” he tells me. But people wouldn’t be better off by avoiding an index fund in order to avoid SpaceX.
Over time, the market has produced a return of about 10 percent a year. But the majority of companies aren’t responsible for that return, Malkiel says. Only 4 percent of stocks give that rate of return, and everything else underperforms. If you own an index fund, you will definitely own a bunch of the stocks that lose money, but you’ll also own that crucial 4 percent. “We know experts can’t determine which ones are going to be good,” he says. “The point is, we don’t know which ones are going to be the best and which ones are going to fail.”
Besides, if you have an index fund with SpaceX in it, and SpaceX loses value, the fund rebalances with fewer SpaceX shares, since SpaceX is proportionately less of the overall market. Lots of companies, including those that are in index funds, go bankrupt every year. The focus isn’t on losses — it’s about gains.
Are there other SpaceX schemes I should be aware of?
SpaceX president Gwynne Shotwell donated shares of the company to Trump Accounts, which are investment accounts for children. The president said the donation was worth $325 million. That is perhaps more alarming than the index funds, because it ties SpaceX very closely to political power.
Let’s say I want to avoid owning SpaceX shares at all. How can I do that?
Besides preferentially investing in the S&P 500 index funds, you might also choose to invest in environmental, social, and governance funds. They generally have higher fees than index funds and don’t perform as well, but if not having SpaceX in your portfolio is a high priority, that might be a way to avoid it — since Musk’s control of SpaceX means the company flunks the “G” part of the requirement. (It may also flunk the “E” part, environment, thanks to the pollution from rockets and AI.) Different ESG funds have different criteria, but someone trying to avoid SpaceX because of Musk might end up with Tesla in their ESG fund — for its electric vehicles, Malkiel says.
