You may have seen headlines about SpaceX going public at a huge valuation, as potentially one of the biggest stock market listings ever.
It was valued as a $1.75-2 trilllion company for it’s IPO (Initial Public Offering – when we can all buy shares in the company as a member of the public)
So the natural question is:
“If I’m invested in a ‘tracker’ or a diversified portfolio… will I suddenly own a big chunk of SpaceX?”
The short answer is: No—not in the way you might expect.
Here’s why.
Big headline numbers don’t tell the full story
When a company lists at a valuation of, say, $1 trillion or more, it’s easy to assume:
- It immediately becomes a major part of stock market indices
- And therefore a big part of your portfolio
But that’s not how it works.
What matters isn’t the total value of the company. It’s how many shares are actually available to buy
In many high-profile IPOs, only a small percentage of the company is sold to the public at first. The rest is often still held by founders, employees, or early investors.
So while the headline valuation may be enormous, the tradable portion is much, much smaller.
Using SpaceX as an example
When SpaceX listed, only a small slice of its shares were available to investors. Only about 4% of it to be exact.
That means it did not enter stock market indices at its full size and, therefore, its initial impact on portfolios is much more limited than you would think.
Over time, more shares may become available—but this usually happens gradually, not all at once. It will take private investors, like Elon Musk, VC funds or other employees who maybe hold locked in shares to decide to sell them over time. They might even never decide to sell…
Index funds don’t jump in overnight
We invest in index funds – funds which hold lots of different companies at once. Today, our current holding of shares is in 7,853 different companies, and if we include bonds and fixed interest, 13,356 individual holdings. (Figures correct on 18th June 2026, taken from EBI Portfolios Core Data Exposure)
So if you think about spreading your eggs in many baskets, we have 13,356 different baskets today.
Another common misconception is that index funds immediately pile in on day one.
In reality:
- Different indices have rules about when new companies are included
- Many require a waiting period
- Some only review changes at set points during the year
So inclusion in the fund is often phased and controlled, not automatic
Even when a company is added quickly, it’s still governed by rules. Not hype. Which of course, whether you love him or hate him, Mr Musk has a reputation for hype.
Not all “passive” portfolios behave the same
It’s also important to remember that not all passive investments are identical
Some funds track the market very closely, but others:
- Apply filters (for example, ESG criteria)
- Focus on certain company characteristics like quality or stability or size
- Only include companies that fit their approach
That means a newly listed company like SpaceX may not be held straight away, or may be held at a much smaller level than the headlines suggest
Diversification does the heavy lifting
Even when companies like SpaceX are added to indices, there’s a key safeguard: Diversification
Most well-constructed portfolios hold thousands of companies spread across all regions and sectors. So even a very large new company typically remains as just one small part of a much bigger picture
What this means for YOU
✔ You won’t suddenly have a large, concentrated exposure to SpaceX – or any new IPO for that matter as Anthropic and Open AI will also be coming to market
✔ Any exposure builds gradually and under strict rules
✔ Your portfolio remains diversified and disciplined
Importantly, we’re not trying to predict whether a company like SpaceX will take us to the moon (or Mars) or fall on it’s face like an exploding rocket at take-off. We also won’t chase headlines and short-term excitement
Instead, the focus remains on:
– Owning a broad range of investments
– Keeping costs low
– Sticking to the long-term plan
So yes, Big IPOs can create a lot of noise. But your portfolio isn’t driven by headlines. It’s built on a structured, disciplined approach that keeps any single company in its proper place.
You might remember us saying that we don’t want to own enough of one company to make a killing, because it could easily bite us and owning too much of one company, could kill us.