Most generalist coverage of mega-IPOs reads from the press release and stops at headline valuation. Real pre-IPO analysis works backward from the document — the S-1 — and reconstructs the structural mechanics that determine whether the listing trades well or badly in the months after pricing. This article uses a hypothetical SpaceX S-1 framework (the same scenario modeled across this site) to walk through the four sections that disproportionately matter: share architecture, institutional positioning, lock-up cadence, and the risk section. The framework is general; the specific numbers are scenario assumptions, not confirmed disclosures.
Share architecture
Two classes, dual votes, no automatic sunset clause. In the modeled scenario, 2.15 billion Class A shares and 270 million Class B shares are outstanding. The first thing a serious reader checks is whether the supervoting class has a time-decay or transfer-conversion mechanism — both are present here, and both materially change the long-term governance picture. Class B converts to Class A on transfer to non-permitted holders, which means founder secondary sales are not just liquidity events — they are governance events. The second thing to check is whether there are anti-dilution carve-outs for the supervoting class on follow-on issuance. This affects how aggressively the company can issue equity for acquisitions without diluting founder control.
Institutional positioning
In the modeled scenario, Alphabet sits at roughly 7.5% of Class A from its long-running Starlink investment, Fidelity holds 6.2% across funds, and Founders Fund anchors 4.8%. The number that matters more than any individual stake is the *concentration distribution* — how much equity is held by named institutions versus employees versus a residual 'other strategic and sovereign' bucket. The scenario modeled here puts roughly 22% in employees and 27% in the residual category — both numbers worth scrutinizing because they materially affect lock-up cliff timing.
Lock-up cadence
Strategic partners typically unlock at T+90 in mega-IPOs, institutions at T+180, and insider tranches — including any secondary founder allocations — at T+365. Each window is a discrete supply event. In the scenario modeled here, the T+180 release would put hundreds of billions of dollars of supply into market float. Whether that supply is absorbed cleanly or causes a Coinbase-style drawdown depends entirely on demand depth at the time of release, which itself depends on macro conditions twelve months away — uncomputable today.
What actually matters to model
The first-day pop is noise. Almost every mega-IPO has volatile early trading, and the variance is dominated by allocation mechanics rather than fundamentals. The information edge is in the supply path: who can sell, how much, and when. Build that map first, then layer in the macro overlay, then the company-specific catalysts. SPCX Ledger lets you stress-test exactly that — every slider in the simulator corresponds to one of the variables a real pre-IPO desk would track, and the underlying math is documented in the methodology page so you can verify the assumptions before trusting the output.