An anticipated low initial float combined with concentrated index buying could lead to a temporary supply-demand imbalance during the early stages of SpaceX's listing. The IPO is expected to be one of the largest in U.S. history, with potential passive fund inflows exceeding $10 billion. Post-IPO, the company's total market capitalization is estimated at approximately $1.77 trillion, with an initial free-float market cap between $75 billion and $86.25 billion, representing a float ratio of only about 4.25% to 4.86%, indicating a relatively limited supply of tradable shares initially.
Given its massive market cap and listing on the Nasdaq, the company is expected to be quickly included in major indices such as the Nasdaq Composite, Nasdaq-100, CRSP, Russell, and MSCI indices, driving phased passive investment demand. Based on verifiable index product sizes, potential passive buying is estimated at roughly $9.1 billion to $11.3 billion; if considering extended market indices and broader passive funds, the upper bound of this range could be revised to $14 billion to $16 billion.
Overall, the initial market impact of SpaceX's listing is not merely about the liquidity drain from IPO fundraising. It is more likely to manifest as a temporary supply-demand tension caused by the "low initial float + concentrated index buying." However, as lock-up periods are lifted in batches following Q2 and Q3 earnings reports, the supply of floating shares will gradually increase, shifting the market impact from short-term demand-driven factors to the release of supply and the digestion of valuations.
The IPO to Set a Historical Record with a Low First-Day Float
The official IPO launch announcement indicates that the roadshow will commence on June 4, 2026. The FWP/IPO FAQ discloses that the final IPO price is expected to be set on June 11, 2026, with shares anticipated to begin public trading on June 12, 2026. The base offering size is 555,555,555 Class A ordinary shares, with an expected offering price of $135 per share, corresponding to a fundraising amount of approximately $75 billion. Additionally, underwriters are granted a 30-day over-allotment option for 83,333,333 shares. If fully exercised, the total offering size would be about 638,888,888 shares, raising approximately $86.25 billion.
Phased Lock-up Expirations to Gradually Increase Post-IPO Float Supply
The post-IPO total market capitalization is approximately $1.77 trillion. According to the Description of Capital Stock section in the S-1/A filing, upon completion of this offering, the company's issued and outstanding share capital will consist of 7,380,196,910 Class A ordinary shares and 5,695,668,265 Class B ordinary shares, totaling approximately 13,075,865,175 shares. There are no issued and outstanding Class C ordinary shares or preferred shares.
Based on the base offering share count, SpaceX's initial free float is about 556 million shares, corresponding to a free-float market cap of approximately $75 billion and an initial float ratio of about 4.25%. If the over-allotment option is fully exercised, the initial free float would be about 639 million shares, with a free-float market cap of roughly $86.25 billion and a float ratio of about 4.86%. At the $135 per share offering price, the post-IPO total market cap is approximately $1.77 trillion.
It is important to note that the $75 billion to $86.25 billion range primarily reflects the new shares issued in the IPO at the initial listing stage. The actual tradable supply will increase as lock-up restrictions are released in phases. According to the Shares Eligible for Future Sale and Underwriting—Lock-up Agreements sections in the S-1/A, starting from the second full trading day after the Q2 earnings release, up to 912 million Class A shares could become unrestricted, representing a market value of about $123.05 billion. If the stock price trades at least 30% above the IPO price and meets trading day conditions, an additional 456 million shares could be released, with a market value of approximately $61.53 billion.
Subsequently, approximately 319 million shares could be released on each of the 70th and 90th days, and about 328 million shares on each of the 105th, 120th, and 135th days. Following the Q3 earnings release, another approximately 1.3 billion shares could be released. Overall, while this IPO features a large offering size, high total market cap, and a low initial float ratio, the phased lock-up expiration schedule will drive a gradual expansion of the free float in the months following the listing.
Potential for Rapid Inclusion in Multiple Indices, with Nasdaq-100 as a Key Catalyst
Based on current index construction rules, SpaceX is expected to be quickly added to several major U.S. broad-market and growth-oriented indices post-listing. The Nasdaq Composite Index is projected for inclusion around June 15, 2026, at the earliest. The Nasdaq-100 Index has fast-entry conditions; if its post-listing total market cap ranks within the top 40 of existing constituents, inclusion is expected around July 6-7, 2026. The Russell 3000 / Russell 1000 indices may include it after the fifth trading day post-listing, potentially by the close of June 18, 2026. The CRSP US Total Market Index is expected for inclusion around June 18-22, 2026. The MSCI USA Index / MSCI ACWI Index could be included around June 26, 2026, if they meet large IPO fast-track criteria.
The S&P Total Market Index / Dow Jones US Total Market Index might be included in late June 2026, pending official announcements. The S&P 500 Index is not expected for inclusion in the short term due to requirements such as at least 12 months of trading history, profitability, liquidity, and Investable Weight Factor (IWF) criteria, with the earliest discussion likely after June 2027.
Low Float Amplifies Weight in Nasdaq Indices, Limited Weight in Broad-Market Indices
SpaceX's low initial free-float ratio leads to significant variations in its projected weight across different index methodologies. The Nasdaq-100 Index uses a modified market capitalization approach, capping low-float stocks at three times their free-float shares, resulting in an estimated weight of about 0.6%-0.7%, making it the primary source of passive fund inflows in this analysis. The Nasdaq Composite Index, which weights closer to total market capitalization, is expected to assign a weight of approximately 3.0%-4.0%, but the assets under management tracking it are significantly smaller than those tracking the Nasdaq-100.
Broad-market indices like CRSP, Russell, S&P Total Market, and MSCI primarily use free-float adjusted market cap, resulting in overall lower projected weights compared to Nasdaq indices. Estimated weights are around 0.12%-0.14% for US total market/broad-market indices, 0.16%-0.26% for growth-style indices, 0.08%-0.12% for the Russell 1000 and US large-cap indices, and 0.07%-0.08% for global broad-market indices.
Additionally, within the S&P system, a conditional scenario exists: if SpaceX is first added to the S&P Total Market Index but does not immediately enter the S&P 500, some "extended market" index products may need to allocate to SpaceX. Since these products cover a narrower stock universe than the total market index, SpaceX's weight within them could be higher, estimated at around 0.6%-0.9%.
Verifiable Passive Inflows Estimated at $9.1-$11.3 Billion, with Upside in Broader Measures
Based on publicly verifiable ETF, mutual fund total shares, and some overseas UCITS product sizes, the potential passive buying scale following SpaceX's inclusion in major indices is estimated at $9.1 billion to $11.3 billion. In terms of timing, passive fund inflows could account for about 10-15% of the free-float market cap before the first lock-up expiration, eventually representing about 2-3% after all lock-ups expire.
Breakdown: Nasdaq-100 related products account for approximately $3.46 billion to $4.04 billion, the largest single source of incremental demand. The Nasdaq Composite Index accounts for about $1.16 billion to $1.55 billion. US total market/broad-market indices account for roughly $3.16 billion to $3.64 billion. Growth-style indices account for about $1.18 billion to $1.79 billion. The Russell 1000 and US large-cap indices account for approximately $60 million to $90 million. MSCI global/ACWI and similar global broad-market products account for about $120 million to $140 million.
If the S&P Completion/extended market conditional scenario is included, passive buying could increase by an additional $580 million to $870 million, shifting the range to about $9.7 billion to $12.1 billion. Under an even broader definition, including institutional separate accounts, CITs, pension passive accounts, model portfolios, more overseas index products, and derivative/market maker hedging flows that are difficult to verify publicly, the passive buying scale has further upside. Estimating an additional 30%-40% of non-public index-tracking funds on top of the verified product base, the upper bound of the range could reach approximately $14 billion to $16 billion.
Negative Impact of Large IPOs Often Front-Loaded, SpaceX's Listing May Have Limited Disruption on U.S. Stocks
An analysis of the top 100 U.S. IPOs by net fundraising since 2000 reveals that large IPOs have a negative but front-loaded impact on the broader market: 1) On a macro level, the S&P 500 Index has historically declined by an average of about 4% in the 60 days leading up to a large IPO's listing date, before resuming an upward trend post-listing, with a median gain of around 3% in the subsequent 60 days. The VIX Index has remained stable around large IPOs, averaging below 20 and only at about the 60th percentile historically, indicating limited market disruption intensity.
2) On a micro level, the median excess return of individual stocks relative to the S&P 500 over the 60 days post-listing reached 11.0 percentage points. The distribution of excess returns is right-skewed, with high-return samples dominating, reflecting strong investor appetite for high-quality large IPOs. In terms of timing, excess returns are primarily concentrated in the first week post-listing, after which the curve tends to flatten, suggesting rapid and sustained valuation premium realization.
3) Furthermore, sector performance diverges significantly. Information Technology, Consumer Discretionary, and Health Care sectors have historically led, with average excess returns relative to the S&P 500 60 days post-listing reaching 48.8, 21.1, and 20.6 percentage points, respectively. The Energy sector has been the weakest performer, with an average excess return of -10.4 percentage points, the only sector to record negative excess returns.
Risk Disclosures: The timing of SpaceX's listing remains uncertain. The timing and scale of index inclusions may fall short of expectations. Model estimates are subject to error.
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