SpaceX Files for IPO: Which Registered Funds Carry the Biggest Combined Exposure

On April 1, 2026, SpaceX filed a confidential S-1 registration statement with the SEC, targeting a $1.75 trillion valuation and a June 2026 listing on Nasdaq. The offering — code-named Project Apex — is expected to raise roughly $75 billion, which would be the largest IPO in history. N-PORT filings, which registered investment companies submit monthly to disclose their holdings, show which funds have been building positions in both SpaceX and xAI heading into this moment. Those two bets are now the same bet: SpaceX acquired xAI in February 2026 in what was reported as the largest corporate merger on record.

One IPO, two companies folded into one

The merger has compressed what was previously tracked as two separate private market exposures into a single outcome. xAI had merged with X (formerly Twitter) in March 2025 at a combined valuation of $113 billion. SpaceX then acquired the combined xAI/X entity in February 2026 — SpaceX valued at roughly $1 trillion, xAI at approximately $250 billion — creating a combined entity with a reported enterprise value around $1.25 trillion. Any fund that held xAI equity now holds a SpaceX subsidiary. The IPO is the first path to public price discovery across all of it.

xAI's last independent funding event was a $20 billion Series E in January 2026 at a $230 billion valuation, backed by Nvidia, Cisco, Fidelity, the Qatar Investment Authority, and others. Its core asset — the Colossus data center complex in Memphis — had reached roughly 555,000 Nvidia GPUs and two gigawatts of AI training capacity by early 2026 at an estimated capital cost of $18 billion, making it the largest single-site AI training installation in the world.

Which funds have the most at stake

Among registered funds, combined SpaceX and xAI exposure — as reported in December 2025 N-PORT filings — is most concentrated in a handful of growth and private-access strategies. Baron Partners Fund stands out at 33.7% of NAV across both entities, with 32.1% in SpaceX across five share classes and 1.6% in xAI. For context, that means roughly one-third of a $9.7 billion fund's reported value is tied to the outcome of a single listing event.

• Baron Partners Fund — 33.7% combined (SpaceX: 32.1%, xAI: 1.6%)
• Baron Focused Growth Fund — 23.0% combined (SpaceX: 19.3%, xAI: 3.7%)
• Destiny Tech100 Inc. (DXYZ) — 19.5% combined (SpaceX: 16.1%, xAI: 3.4%)
• Baron Asset Fund — 19.2% combined (SpaceX: 12.5%, xAI: 6.7%)
• Baron Global Opportunity Fund — 18.7% (SpaceX only)
• The Private Shares Fund — 16.7% combined (SpaceX: 13.6%, xAI: 3.1%)
• Baron Opportunity Fund — 11.6% combined (SpaceX: 8.8%, xAI: 2.8%)
• StepStone Private Venture and Growth Fund — 10.7% combined (SpaceX: 7.3%, xAI: 3.5%)

Bloomberg reported in February 2026 that Baron Capital's SpaceX ETF stake in its Baron First Principles ETF was approaching the SEC's 15% limit on illiquid assets in registered funds — a constraint that limits how large a private position can grow inside a publicly traded vehicle. An IPO would convert those holdings to publicly traded shares, dissolving that ceiling.

The concentration vs. scale split

The fund with the largest absolute dollar exposure is not a concentrated private-equity vehicle — it's Fidelity Contrafund, a $176 billion diversified growth fund. Contrafund held approximately $5.8 billion in SpaceX and $400 million in xAI as of December 31, 2025, totaling roughly $6.2 billion across both entities inside a fund where the combined weight is just 3.5%. Contrafund actually reduced its SpaceX share count by roughly 6% between Q3 and Q4 2025 — trimming about 294,000 shares — while the position's dollar value nearly doubled due to repricing. Fidelity Advisor New Insights Fund held another $1.3 billion combined at a 5.2% weight.

The two stories — Baron's concentration and Fidelity's scale — describe different kinds of risk. A NAV that is one-third a single pre-IPO stock is a different proposition than a $6 billion holding inside a $176 billion fund, even if both positions are marked using the same unobservable Level 3 inputs.

How funds priced SpaceX heading into the filing

The Q4 2025 repricing provided an early signal. Among funds that held unchanged SpaceX share counts between Q3 and Q4 2025, the most common mark change was approximately +98.6% — a near-doubling of implied per-share value, applied consistently across the Baron funds, The Private Shares Fund, and several smaller holders. Fidelity's funds came in at +88.9% on unchanged balances; BlackRock's fixed-income-oriented funds applied +54.4%. Three distinct pricing clusters for the same underlying company in the same quarter is a common pattern in Level 3 private assets — different fund families update valuations at different intervals and using different reference transactions. The IPO will produce a single public price.

For xAI, equity holders applied a mark change of approximately +106.4% — Baron funds, Fidelity growth strategies, and others holding xAI equity all in the same direction. Credit funds holding xAI debt showed marks of roughly +1–2%, consistent with bond coupon accrual rather than equity repricing. The credit holders represent a separate category: Western Asset, Lord Abbett, Apollo, and Oaktree credit vehicles that participated in xAI's debt issuances hold small bond positions — they are exposed to xAI's credit profile, not to the IPO's equity outcome.

Destiny Tech100 trades at a premium to its own marks

One position worth noting separately: Destiny Tech100 (DXYZ), a NYSE-listed closed-end fund with SpaceX at roughly 16% and xAI at 3.4%, jumped approximately 18% on the day the SpaceX IPO filing became public. DXYZ shares had already been trading at a roughly 50% premium to the fund's reported NAV heading into April 2026 — meaning the market was already pricing SpaceX above what Destiny itself reported. When a closed-end fund trades at a large premium to NAV, it can reflect market expectations that the underlying private valuations will be marked up further, or that a liquidity event is approaching. The IPO filing, if it proceeds, tests both assumptions simultaneously.

Notes

Holdings data is drawn from N-PORT filings covering Q3 and Q4 2025 (September 30 and December 31, 2025). SpaceX and xAI position data reflects fund-reported Level 3 fair value estimates. The SpaceX–xAI merger closed in February 2026; the combined exposure figures reflect pre-merger filing periods, when both companies were tracked separately. Individual fund holdings and history are available on FilingFrog through the fund section. Cross-fund views for each company are at SpaceX and xAI.