A SPAC is a shell company that lists on an exchange with no business, then merges with a private company to take it public. A traditional IPO is the private company selling its own shares to the market, with underwriters and price discovery in between. The practical difference: a SPAC skips much of that machinery, and the safeguards it skips land on the investor.
That trade-off outlived the 2020–2021 boom. The hype cycle moved on, but the structure stayed. So the question of spac vs traditional ipo is no longer about which is fashionable. It is about what each route actually does to pricing, dilution, and who is left holding the diligence work.
According to Wikipedia's entry on special-purpose acquisition companies, a SPAC is a shell corporation listed on a stock exchange that acquires or merges with a private company through a procedure requiring fewer regulatory filings and carrying fewer investor safeguards than an IPO. The U.S. Securities and Exchange Commission describes SPACs as vehicles created to pool funds for a future merger, usually before any target has even been identified.
How does a SPAC merger actually work?
A SPAC raises money in its own IPO first. It has no operations and no assets beyond cash. By market convention, 85% to 100% of the proceeds sit in a trust, usually invested in government bonds, while the sponsors hunt for a target. The target must have a fair market value of at least 80% of the SPAC's net assets at the time of acquisition.
When a target is found, the deal is put to a shareholder vote. If more than 50% approve and less than 20% vote to liquidate, the deal closes and the acquired company is listed. If more than 20% want out, the trust is unwound and funds go back to shareholders pro rata.
One regulatory change matters here. Regulators decoupled the right to vote from the right to redeem. Investors can now vote against a deal and still take their money back. Fidelity's SPAC explainer notes the effect plainly: this change has led to most proposed deals going through as planned by SPAC management.
Where does the money go?
This is the part the boom glossed over. SPAC sponsors typically receive roughly 20% of the common equity in the SPAC, plus 3% to 5% of IPO proceeds, for essentially no capital at risk on the same terms. Add banker fees, lawyer fees, and payments to early investors, and the arithmetic gets ugly.
According to Stanford law professor Michael Klausner, cited in the Wikipedia entry, one reason SPAC companies have performed so poorly is that the company going public may receive only about 50% of all the money investors supplied. The rest is consumed by fees and sponsor economics.
A traditional IPO has fees too. Underwriting discounts are real, and the roadshow is not free. But the IPO route at least runs a market-based price discovery process. The SEC has stated that unlike a traditional IPO, where the company and its securities are valued through market-based price discovery, SPAC managers are solely responsible for deciding how to value the private company and how much the SPAC pays for it.
Who does the diligence?
In a traditional IPO, underwriters, lawyers, and regulators all press on the same document. The S-1 is a disclosure exercise with real teeth, and our guide to red flags in the S-1 fine print covers what to look for. In a SPAC merger, the target company produces forward projections that a conventional IPO would rarely permit, and the burden of judging them shifts to shareholders. Readers following this should also see How to Read an S-1: Red Flags in the Fine Print.
Fidelity flags the flip side directly: while SPACs offer the private owners more limited financial reporting requirements, investors may have access to less information. The sponsor picks the target, negotiates the price, and holds the equity upside. The public shareholder gets a proxy statement and a deadline.
That is the diligence burden in one sentence. The SPAC structure did not eliminate the work of evaluating a company. It moved that work from a regulated underwriting process onto individual investors, many of whom were told the sponsor had already done it.
What does the post-boom record show?
The record is blunt. Academic analysis cited by Wikipedia shows investor returns on SPAC companies post-merger are almost uniformly negative, even though investors may earn excess returns immediately after the merger closes. Proliferation of SPACs has historically accelerated around economic bubbles, including the 2020–2021 period.
None of this means every SPAC deal fails, and it does not mean every IPO succeeds. It means the average outcome differs, and the difference traces back to structure: sponsor dilution, negotiated pricing, and thinner disclosure. A company that priced itself through an IPO roadshow faced market discipline before its first trading day. A company that arrived by reverse merger set its own price with a willing counterparty.
What this means for founders and investors
For founders, the honest comparison is about control and speed. Fidelity lists the reasons companies choose SPACs: faster access to public markets, an option for highly leveraged companies that might struggle in an IPO, and the ability for major shareholders to sell a higher percentage while avoiding lock-up periods. Those are real advantages, and they explain the appeal even now. Our breakdown of how IPO pricing and lock-up periods work shows what a company gives up to get them. We covered a connected angle in How IPO Pricing and Lock-Up Periods Actually Work.
For investors, three checks matter more than the sponsor's résumé:
- Follow the dilution. New SEC rules adopted in 2024 require potential dilution to be displayed prominently on SPAC filings, rather than scattered and unclear as before.
- Watch the redemption rate. Heavy redemptions mean sophisticated holders walked, and the PIPE filling the gap sets the real price.
- Read the projections as claims, not forecasts. In a SPAC, the target wrote them with a deal to close.
The SPAC route still exists, and it still suits some companies. But the hype cycle did everyone one favor: it made the fee math and the dilution visible. Compare a SPAC deal against a priced IPO the way you would compare any two offers — by what reaches the company, what the shareholder owns afterward, and who verified the numbers. The rest is packaging.
