Holding SpaceX After IPO: How to Build Your Portfolio Around It Like an Institutional Investor

The prior articles in this series made the case for diversification — and I'll make it one more time, briefly, because the data is hard to ignore: roughly 96% of individual stocks over long periods match or underperform Treasury bills. And more than 70% of companies underperform the market after IPO. The math reliably favors diversifying (via selling or exchanging) more rather than less.

Disclaimer over. If you're still reading, you've decided to hold a significant SpaceX position, so let's dive into how best to do that.

I have clients who held large concentrated positions in companies they believed in, did it right, ran the process, and came out with extraordinary results. Others who did the *exact same* and came out very disappointed. That's the known risk here; holding a lot of a single company means it's very painful when you're wrong.

But the key phrase from the above is did it right. Holding a concentrated position should not be passive in any way — it's a deliberate, ongoing discipline. The same discipline that institutional investors apply to every position they run with conviction: a written thesis, defined exit rules, a position size they've stress-tested, and a regular cadence of re-underwriting the decision.

This article is the playbook for doing it that way.

Step 1: Know What You Actually Own

Before you can plan around a concentrated SpaceX position, you need an honest accounting of your full exposure. Most employees underestimate this by 30–40% because they only count what's already in their brokerage account. Your full SpaceX exposure has 2-3 layers:

Layer 1: Vested shares and exercised options. What you own today and could sell tomorrow. This is the number most people start and stop with.

Layer 2: Unvested grants. Every share on a future vesting schedule is real SpaceX exposure — it just isn't liquid yet. If you have $3M vesting over the next three years, that's $3M of additional concentration that's going to show up whether you plan for it or not. And the value of those grants moves 1:1 with the stock price.

[Partial] Layer 3: Career capital. Your salary, bonus, refresh grants, and professional network are all partially tied to SpaceX's trajectory. If the company struggles meaningfully — stock down 60%, business model challenges, competitive disruption — your compensation and employment stability feel that. That doesn't show up on a brokerage statement. But it absolutely shows up in your financial life.

The total of layers 1 and 2 are your actual SpaceX exposure, and every planning decision in this article needs to be made against that number, not just the shares in your account.

For most SpaceX employees I work with, that total exposure is somewhere between 70% and 90% of their complete financial picture. That's the honest starting point for everything that follows.

Step 2: Write the Investment Thesis — Legitimately

If you're going to hold a significant position in any single company, you owe it to yourself to write down exactly why. Not a gut feeling. Not "I work there and I know how good this is." An actual investment thesis.

A legitimate thesis for holding SpaceX after IPO has to answer three questions:

1. Why will SpaceX be worth more in the future than it is today, at this valuation?

The emphasis on "at this valuation" matters. If SpaceX IPOs near the $1.5 to $2.0 trillion range that's been widely discussed, that stock price is richly valued and fully reflects the market's best estimate of all future SpaceX business: tons of Starlink growth, Falcon 9 dominance, data centers in space, repeatedly launched reusable rockets, Grok AI, and more. For the stock to significantly outperform after the IPO, something (or multiple things) new, that isn't yet expected, has to materialize to boost the share price. This step is explicitly naming what that something is.

Here's the difference between a weak thesis and a strong one:

Weak: "SpaceX is executing better than any competitor and Starlink is growing fast. I believe the stock will be worth significantly more in five years."

This tells you nothing actionable. You can't track it. You can't falsify it. And most importantly, it's not new or different from what the market is already pricing in.

Strong: "Starlink's TAM in maritime, aviation, and enterprise connectivity is underrepresented in current analyst models. I believe the unit economics of Starship will reduce launch costs dramatically enough to open revenue streams that aren't yet priced in — including potential government broadband contracts and international market penetration that's still in the single-digit percentages. By 2030, I believe Starlink reaches $40–50B in annual revenue, which at a 15–20x multiple supports a valuation materially above IPO price. My five-year target reflects 2–3x appreciation, driven primarily by Starlink margin expansion as the constellation matures. Additional optional upside is the formalized tests and success of data centers in space."

That's a thesis you can track, update, and act on. Write yours to this standard.

And if you can't, or don't want to, that's a strong sign that you should revisit your decision to hold a significant amount of SpaceX stock.

2. What would change your mind?

This is the question most investors skip — and it's the most important one. If you haven't defined what would make you sell, you don't have a thesis. You're just holding and hoping. Hope is not a strategy (and can be a great way to turn a $5 million position into $500k).

Spend real time on this question. Specific signals that might belong in your answer:

• Starlink subscriber growth stalls materially below your modeled trajectory by a specific year

• A well-capitalized competitor successfully launches a competing constellation with better unit economics

• Regulatory developments meaningfully limit Starship operations or international Starlink access

• SpaceX loses anchor government contracts you're counting on in your model

• Post-IPO earnings reports reveal margin dynamics that don't support your valuation thesis

• Valuation multiples expand to a level where the upside case no longer justifies the concentration risk

• Key leadership exits the company

You don't need all of these. But you need yours — written down, specific enough that you'd recognize the signal if it arrived.

3. How long are you willing to wait?

A three-year thesis looks different from a ten-year thesis. Define yours, because the time horizon determines whether a 30% drawdown in year one is expected volatility within your plan, or a signal that something is wrong.

Write the whole thesis down. Date it. Put it somewhere you'll actually find it. And schedule periodic check-ins where you do real work (and invest real time) to review and re-validate or invalidate your thesis.

Step 3: Build the Rest of Your Financial Plan Around the Concentration

Here's another area where people who hold concentrated positions tend to make a critical mistake: they treat the concentrated position as the plan, rather than building a plan around it.

Holding a large SpaceX position doesn't mean the rest of your financial life pauses. It means the rest of your financial planning has to be constructed specifically to absorb what happens if SpaceX goes wrong.

Ensure you have all the cash you need to cover obligations over the next 12-24 months. Before the lockup expires, make sure every near-term financial goal you have is fully funded in cash (not from the shares you're keeping). Home purchase, tax payments, ISO exercise costs, career optionality — whatever your life needs in the next 12 to 24 months needs to come from liquid assets, not from a bet on where SpaceX trades.

The concentrated position should represent upside and long-term wealth building. It should not be load-bearing for things that have to happen regardless of what SpaceX does.

Estimate and pre-fund your tax obligations. Holding a large position doesn't mean avoiding taxes; it means timing them. As your systematic selling plan generates proceeds each quarter, work with your CPA to ensure you're making adequate estimated tax payments and/or reserving the cash for when the tax bill is due. Nothing disrupts a disciplined hold plan faster than a surprise tax bill that forces a reactive sale.

Build a diversified investment portfolio with your concentrated position in mind. The proceeds from shares you sell need to be strategically considered and allocated. With the heavy concentration risk you'll have/keep of SpaceX, the rest of the portfolio may likely want to build around that. Different asset classes, geographies, sectors, or in many cases short duration, high quality bonds (i.e. very low risk-taking to help offset the very high risk taken with SpaceX).

There is far too much to cover relating to this to get into the details here. But the key point is that SpaceX is your big bet. If it does well, your wealth will rise significantly. And if it declines materially, your diversified portfolio should help provide you with financial stability.

You're not choosing between them — you're running both simultaneously with a purpose.

Ensure you consider your unvested grants. If you're planning to stay at SpaceX for two or three more years, your concentration isn't fixed; it's growing with every vest date. A $2M hold position today, plus $3M vesting over three years, is a $5M SpaceX bet by the time it's fully delivered. Make sure your diversified portfolio scales alongside the vesting — not just at lockup expiration.

Step 4: Set Exit Rules Before the Stock Starts Moving

The ideal time to set exit rules is before you're watching a live ticker. It can definitely be done after (and should be if you're reading this post IPO), but it becomes psychologically harder when the price is changing every day. There are three types of exit rules worth having:

1. Price-based rules. These are mechanical — they take the in-the-moment decision out of your hands.

• "If SpaceX drops more than 40% from my cost basis within two years, I'll sell half of my target long term holdings and reassess the thesis."

• "If the stock doubles within 18 months and my long-term holdings represent more than 25% of my total net worth again, I'll trim back to 15%."

These aren't predictions about where the stock goes. They're commitments about what you'll do regardless. This is risk management and wealth preservation 101.

2. Thesis-based rules. These tie your exit trigger to the specific thing you said you were betting on.

• "If Starlink subscriber growth is materially below my model by 2027, I'm reassessing and likely reducing by 30%."

• "If a direct competitor successfully demonstrates comparable unit economics at scale, I'm reassessing and likely reducing by 50%."

Every item on your "what would change my mind" list from Step 2 belongs in here as a rule.

3. Time-based rules. These force a real evaluation at regular intervals instead of passive drift. More on this in Step 6 below.

Step 5: Run the Downside Scenario All the Way Through

The most important thing you can do with a concentrated position is make an honest model of what happens if you're wrong.

Not a catastrophic scenario — a realistic bad case. SpaceX IPOs and in the 18 months that follow, the stock gives back 40–50% as the market reprices post-lockup selling pressure and early earnings results come in below elevated expectations. That's not a tail event. That's something like what happened to a substantial portion of 2020–2021 IPOs, including companies with genuinely strong businesses.

At that price, run the full picture:

• What is your long term holdings bucket worth?

• What is your total net worth, including the diversified portfolio from your prior sales?

• Can you still fund your essential life goals?

• Do your exit rules trigger? What do you do?

• How does your thesis hold up against what's happened in the business, or does the decline reflect a thesis-breaking development?

The goal of this exercise isn't to scare you into selling everything. It's to make sure you can genuinely say: if this goes wrong, I've planned for it and I'll be okay. If you can state that honestly — with the numbers in front of you — you can hold with real conviction rather than hope.

If you can't stand by that, it's useful information. Reduce the position until the downside scenario produces an answer you can live with.

Step 6: Manage It Like an Investment — Every 3-6 Months

A concentrated position is not passive. It requires ongoing maintenance. Every 3-6 months, sit down with your thesis document and ask:

• What did I expect to happen in the business? Did it happen?

• What's changed (in SpaceX's business, in the competitive landscape, in the macroeconomic environment) that's relevant to my thesis?

• Does my thesis still hold at the current valuation?

• Have my personal financial circumstances changed in a way that changes how much risk I should be carrying?

• Do my exit rules still make sense, or do they need to be updated?

This review doesn't have to take long. Ninety minutes, honest engagement with the thesis, an explicit decision to hold or adjust. The discipline is the point — you're making an active choice to hold, not drifting into it.

I've seen concentrated positions go wrong more often from this kind of drift than from any single bad decision. The 25% drop is manageable when you have a plan. It becomes unmanageable when you've been holding on autopilot and suddenly realize you no longer know why.

The One Question I Ask Every Client

Before we finalize any hold decision, I ask one question:

If you woke up tomorrow and SpaceX stock was cut in half — would you be okay?

Not comfortable. Not thrilled. But okay: financially stable, still on track, no life-altering decisions required.

If the answer is yes, given the full picture of your plan, you might be sized and structured appropriately.

If the answer is "I'd have to delay retirement" or "I'd have to pull back on something important" it means you're holding too much, or you haven't built the plan around it correctly yet. And you need to fix the plan.

To Recap — Because This Needs to Stay with You

Holding a significant SpaceX position after the IPO is a legitimate strategy, but only when it's a real strategy.

That means: a written thesis with specific catalysts and specific falsifying signals. Exit rules set before the stock moves. A financial plan built around the concentration, with essential life goals funded independently. A diversified portfolio that provides stability alongside the concentrated position. A downside scenario you've modeled all the way through and can genuinely live with. And frequently scheduled reviews that keep you in active relationship with the decision rather than passive drift.

The employees who hold concentrated positions well — who come out the other side with extraordinary outcomes — aren't the ones who only got lucky. Yes, they did get lucky (the statistics on single company risk prove that), but they also did this work. They held because they chose to, knew exactly why, and had a plan for every scenario including the bad (and very bad) ones.

That's the difference between holding intentionally and holding by default. And at these valuations, with this much on the line, the difference matters enormously.