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IPOs & SPACs

Updated Jun 24, 2026 at 2:35pm

Research Draft High 1,176 words

An initial public offering (IPO) is the first sale of a private company's shares to public investors; a special purpose acquisition company (SPAC) is a cash-shell that IPOs first, then later merges with a private operating company to take it public (a "de-SPAC"). Both are how companies cross from private to public markets, and both are classic event-driven / special-situations terrain because they create predictable structural moments — pricing, lock-up expiry, redemption deadlines, de-SPAC votes — that move price for reasons unrelated to fundamentals. The core tension is the same in both: the sell-side (issuers, sponsors, underwriters) is selling at a moment of maximum optimism, and the empirical record shows public buyers who hold past day one tend to underperform. They are mechanisms for transferring a private asset to the public, not, on average, for gaining alpha by buying it.

How it's formed

Traditional IPO. The issuer hires investment-bank underwriters (the lead is the bookrunner). Through bookbuilding — a roadshow to institutions plus an order book — the syndicate sets an offer price, then allocates shares (heavily favoring institutional clients) the night before trading opens. Standard mechanics:

  • Greenshoe / over-allotment option: underwriters may sell up to ~15% extra shares and buy them back to stabilize the aftermarket price (named for the 1963 Green Shoe Manufacturing IPO).
  • Lock-up period: insiders and pre-IPO holders are contractually barred from selling, typically 90–180 days. This is negotiated, not SEC-mandated; expiry is a known supply-shock date.
  • Quiet period (analyst "blackout"): a post-IPO window before underwriters' analysts may publish research. The historically cited figure was ~25 days, but FINRA Rule 2241 now generally sets a 10-day quiet period after the offering (and a short blackout around lock-up expiry) for managers/co-managers; the JOBS Act further relaxed it for emerging-growth companies. Treat "25 days" as a legacy convention, not the current rule.
  • Direct listing is an alternative with no new capital raised, no underwriter price-setting, and no lock-up — used by companies that don't need cash (e.g. Spotify, Coinbase).

SPAC. A sponsor raises a blank-check shell at a standard $10.00/unit (a share plus a fraction of a warrant), parks the cash in trust, and has ~18–24 months to find and merge with a target. Key structural pieces:

  • Sponsor "promote": the sponsor typically receives ~20% of post-IPO shares for a nominal sum — a large dilution embedded in the structure.
  • Redemption right: any public shareholder may redeem at ~$10 + interest at the merger vote, and keep the warrants — an essentially riskless option that decouples who-votes-yes from who-stays-invested.
  • Warrants/rights: free sweeteners that dilute post-merger holders.

How it's used in practice

For issuers/sponsors, these are capital-formation and liquidity events. For traders and event-driven investors, the recurring playbook items are the structural dates, not the story: shorting or hedging into lock-up expirations (anticipating insider supply), trading the quiet-period end (initiation reports), and, on the SPAC side, the near-arbitrage of buying below trust value and redeeming — the documented "SPAC arbitrage" where pre-merger holders capture the trust floor with optional upside. Allocation matters enormously: in a hot IPO, the day-one "pop" accrues to whoever got an allocation at the offer price, not to the retail buyer who buys at the open. Buying an IPO in the open market is buying after the underpricing has already been paid out.

Adoption, debate & evidence

IPO underpricing is one of the most robust anomalies in finance. Using Jay Ritter's (University of Florida) long-run U.S. dataset, average first-day returns ran ~7% in the 1980s, ~15% in 1990–1998, spiked to ~65% in the 1999–2000 internet bubble, and have averaged roughly 17–18% in the 2001–2023 era. Whether this is a "cost" to issuers or rational compensation is contested; leading explanations include the winner's curse (uninformed buyers only get full allocations of bad deals), signaling, information cascades, and agency/spinning (banks underprice to reward favored clients) — Loughran & Ritter argue agency explanations grew more important over time.

Long-run underperformance is equally documented. Ritter (1991) found IPOs bought at the first-day close underperformed matched firms by ~29% over three years, worst for firms that went public in high-volume "window of opportunity" years — consistent with periodic investor over-optimism about young growth firms.

SPACs are the harsher case. Klausner, Ohlrogge & Ruan's A Sober Look at SPACs found the structure's median dilution (promote + fees + warrants + rights) equaled ~50% of cash raised in the IPO — costs borne by post-merger shareholders, not the target. Post-merger performance has been poor: studies cited in European Financial Management (Kiesel et al., 2023) report average abnormal returns (from the merger announcement) of roughly −14% at 12 months and −18% at 24 months for public investors; and per Klausner & Ohlrogge's Was the SPAC Crash Predictable? (Yale Journal on Regulation, 2023), SPACs merging July 2020–December 2021 had fallen on average ~62% by December 2022 (mean price ~$3.85 vs. the $10 baseline; roughly −44% vs. Nasdaq, −51% vs. Russell 2000). Those authors identify net cash per share — not redemptions alone — as the primary statistical predictor of post-merger price, though high redemptions worsen the cash shortfall. The 2020–2021 SPAC boom and subsequent crash are widely treated as a cautionary mania.

Strengths & limitations

IPOs work as the primary route to public capital and liquidity, and the underpricing pop is real if you receive an allocation. The reliable, exploitable edges for outsiders are structural and mechanical — lock-up supply, redemption arbitrage, index-inclusion flows — not "the company is good so buy the IPO." They fail for buy-and-hold investors who chase hot offers at the open: that is precisely where the underperformance evidence concentrates. The #1 misuse is treating an IPO/de-SPAC as a fundamental investment at the offer moment, ignoring that you are transacting against the best-informed sellers at peak narrative. For SPACs specifically, the second great misuse is ignoring dilution and redemption mechanics — the $10 nominal price is not $10 of value in the post-merger entity.

Sources

Dispute flags: whether underpricing is a "cost" vs. rational equilibrium is genuinely unsettled. SPAC dilution magnitude is contested — Klausner et al.'s ~50% figure is challenged by industry-aligned work (e.g., Committee on Capital Markets Regulation) arguing redemptions mitigate it; the post-2021 return evidence, however, is broadly consistent across studies.