Going Public and IPOs, Explained

In brief

• An IPO is a company's first sale of shares to the public. It turns a private business into a listed company whose shares anyone can trade, and brings a new set of legal duties.
• Companies go public mainly to raise large amounts of capital. They also gain shares they can use for acquisitions, liquidity for early investors and employees, and credibility with customers and governments.
• Deep tech is where the need is sharpest. Quantum computers and small modular reactors take years and billions to build. In 2026, two traditional IPOs in these sectors each raised more than $1 billion, and several more companies listed through SPAC mergers.
• There is more than one route to the market. A traditional IPO, a SPAC merger, a direct listing and a dual listing each carry different costs, timelines and risks.
• The law's central demand is honest disclosure. In the US, a company is liable almost automatically for material errors in its offering document. Since 2024, the same liability applies to financial projections in SPAC deals.

Examples are hypothetical unless a source is cited. This article is general information, not legal or investment advice.

1. What an IPO is

An IPO is two legal events at once: the company offers shares to the public, and those shares are admitted to trading on an exchange such as Nasdaq, the NYSE or Euronext.

• The offer requires a detailed disclosure document (a prospectus or registration statement) and makes the company legally responsible for its contents. In the US this falls under the Securities Act of 1933; in the EU, under the Prospectus Regulation (EU) 2017/1129.
• The admission to trading makes it a listed company, with ongoing duties: regular financial reports, rules against insider trading and market manipulation, and exchange governance standards.

In plain terms. Before the IPO, a company answers to a small group of investors under private contracts. After the IPO, it answers to the whole market under public law.

New shares and existing shares

• In a primary offering the company creates new shares and keeps the money.
• In a secondary offering existing shareholders sell and keep the money.

Deep-tech IPOs are mostly primary: the point is to fund the business, not to let founders cash out.

Issuing new shares dilutes existing holders. In the example below, a company with 100 million shares sells 20 million new shares at $10 and raises $200 million. The founder still holds 30 million shares, but they are now 25% of the company instead of 30%.

2. Why companies go public

The main reason is capital. For deep-tech companies, the scale they need often exceeds what private investors alone can provide.

Why now, for quantum and nuclear

• From lab to factory. Both sectors are shifting from prototypes to industrial production: plants, supply chains and teams must be built before revenue arrives.
• Demand for power and compute. Much recent investor interest comes from AI data centres' electricity needs. X-energy has agreements with Dow, Amazon and Centrica (Yahoo Finance). The quantum listings came as the US IPO market recovered on appetite for AI and frontier technology (The Quantum Insider).
• Public money alongside private capital. Government programmes and national labs are major funders in both sectors. As Xanadu completed its listing, it was negotiating up to CAD 390 million in support from the governments of Canada and Ontario, on top of the listing proceeds (SEC filing).
• The window is open. By July 2026, roughly thirty SPACs were reportedly searching for quantum targets (PostQuantum). In nuclear, IPOs and SPAC deals have continued even as market returns cooled (Energy Intelligence).

3. How an IPO works, step by step

A traditional IPO follows a set sequence: prepare, file, market, price, trade, close. Preparation takes the longest; the final steps happen in days.

1. Preparation (often 12 to 24 months). Accounts audited to public-company standards, independent directors on the board, a tidy share structure, banks and lawyers appointed.
2. Confidential filing. In the US, a draft registration statement can go to the SEC in private. SEC staff comment; the company revises.
3. Public filing. The registration statement (Form S-1, or F-1 for many foreign companies) becomes public: business, risks, finances, management.
4. Launch and roadshow. The company sets a price range and presents to investors. Banks collect orders: this is bookbuilding.
5. Pricing. Once the SEC declares the registration effective, the final price and share count are fixed based on demand.
6. First day of trading. Shares trade freely on the exchange.
7. Closing. A few days later investors pay, shares are delivered and the company receives the money.
8. Lock-up. Insiders usually agree not to sell for a period after the IPO, typically 180 days.

A real timeline: X-energy, 2026

X-energy, a small modular reactor developer, went from launch to closing in 12 days.

In plain terms: bookbuilding. The price range is the company's opening offer. If investors order far more shares than are available, the company can raise the price, sell more shares, or both. That is what "upsized and priced above the range" means.

Both of 2026's large deep-tech IPOs priced about 20% above the top of their first range: Quantinuum at $60 against $45 to $50, X-energy at $23 against $16 to $19.

4. Four routes to the market

"IPO" is often used loosely for any way of going public. Legally there are four distinct routes.

How a SPAC merger works

In plain terms. A SPAC (special purpose acquisition company) is a listed cash box. It raises money in its own IPO, holds it in trust, and has limited time to merge with a private company. After the merger, the private company is the listed company.

The catch is redemptions: before the merger, SPAC shareholders can take their money back. If many do, the trust shrinks. That is why most SPAC deals include a PIPE (private investment in public equity): professional investors who commit cash in advance. Infleqtion's CEO cited speed as the reason for choosing a SPAC, against 18 to 24 months for a traditional IPO (SEC filing).

Real example: newcleo. When it agreed its SPAC merger, up to $209 million sat in the SPAC's trust before redemptions (Investing.com). At closing in September 2026, only $31 million of it arrived; the PIPE supplied $216 million, for $247 million in total (Investing.com).

Figure 3. Redemptions in real life. Up to $209 million sat in the SPAC trust before redemptions; $31 million arrived at closing. The PIPE supplied $216 million, for $247 million in total. The redemption figure is implied from the two published numbers. Sources: Investing.com, newcleo.

5. The rules that apply

Every listing is governed by securities law. Deep-tech listings add sector rules: export controls and investment screening for quantum, licensing and ownership limits for reactors.

United States

• Securities Act of 1933 governs the sale. No public sale until the registration statement is effective (Section 5). A material misstatement or omission makes the company liable almost automatically (Section 11); directors, banks and auditors are liable unless they show proper checks.
• Securities Exchange Act of 1934 governs life afterwards: periodic reports, insider trading, disclosure of large holdings.
• Emerging Growth Companies. The JOBS Act gives companies with revenue below $1.235 billion (SEC) lighter rules: two years of audited accounts instead of three, and up to five years' exemption from an auditor's report on internal controls. Oklo reported itself as an EGC after listing (SEC filing).
• SPAC rules since 2024. SEC Release No. 33-11265 removed the "safe harbor" for projections in SPAC deals, required their assumptions to be disclosed, and made the target company directly liable for the document (PostQuantum summary).

Example: why every word counts. A prospectus says a company has "10 logical qubits". In fact they only detect errors; they do not correct them. Investors buy at $20; when the truth comes out, the price falls to $12. Investors can sue without proving intent to mislead, and the company cannot defend itself by saying it was careful.

Example: before and after 2024. In 2021 a SPAC target could present "revenue of $500 million by 2026" with strong legal protection. Today the same forecast needs documented assumptions and carries the same liability as in an IPO.

European Union: the Listing Act

Regulation (EU) 2024/2809 aims to make EU markets cheaper to access. Changes phased in on 4 December 2024, 5 March 2026 and 5 June 2026 (Sullivan & Cromwell).

Once listed in the EU, the Market Abuse Regulation requires prompt publication of inside information. If a reactor developer signs a supply deal worth a large share of future revenue, it must announce it promptly or formally delay; until then, nobody who knows may trade.

Sector rules: quantum

• Export controls. Quantum technology falls under dual-use controls (Regulation (EU) 2021/821; US Export Administration Regulations). The prospectus must explain restricted markets and required licences.
• Investment screening. In the Netherlands, the Vifo Act has required security screening of investments in sensitive technologies since June 2023, and quantum is designated highly sensitive (Quantum Delta NL). A large PIPE stake may need clearance before closing.

Sector rules: nuclear

• Licensing. US reactors need Nuclear Regulatory Commission (NRC) approvals: design certification, construction permit, operating licence. NuScale's design became the first SMR design certified by the NRC, with the rule taking effect in February 2023 (Federal Register).
• Foreign ownership limits. The Atomic Energy Act (Section 103d, 42 U.S.C. § 2133(d)) bars reactor licences for entities owned, controlled or dominated by foreign interests (NRC). The ADVANCE Act of 2024 created limited exceptions, which an NRC rule scheduled to take effect on 7 July 2026 implements (Federal Register). For a listed company anyone can buy into, shareholder monitoring becomes a legal issue.
• Fuel. Many advanced reactors need specialised fuel in limited supply; X-energy makes its own TRISO-X fuel through a wholly owned subsidiary (S-1).

6. Case studies: quantum

Five dedicated quantum companies listed in the US between February and July 2026: one traditional IPO and four SPAC mergers.

Quantinuum: the traditional IPO

Formed in 2021 from Honeywell's quantum division and Cambridge Quantum, Quantinuum raised its range once (IPOScoop), then priced above it at $60, selling 28 million shares (Quantinuum). The prospectus was candid: first-quarter 2026 revenue fell to about $5.2 million from $19.1 million, and the net loss widened to about $136.5 million (CNBC).

What it shows: a billion-dollar IPO can succeed despite falling revenue. Investors priced the technology, the governance and a large industrial shareholder, Honeywell, which kept control.

IQM: a European company on Nasdaq

IQM, founded in 2018 in Finland, signed its SPAC merger on 22 February 2026, closed on 1 July, and began trading on Nasdaq on 2 July alongside a Helsinki listing (IQM 6-K). It reported 18 systems delivered, about €31 million in 2025 revenue and a €67 million order book (TradingView). A lukewarm debut was linked in part to a frank warning that "large-scale commercial traction of quantum computing technology may never occur" (TechCrunch).

What it shows: a European company can list in New York through depositary shares while keeping a home listing. Honest risk factors may cost something on day one but protect against lawsuits later.

Xanadu: listing as a funding necessity

Xanadu closed its SPAC merger on 26 March 2026. Its first annual report shows 2025 revenue of about $4.6 million, a net loss of about $70.7 million, and cash of $16.2 million at year-end (StockTitan).

The first wave: a warning on projections

IonQ (2021), Rigetti and D-Wave (2022) listed through SPACs (DCD) when projections still had legal protection. A July 2026 analysis estimates the group delivered about 12 cents of every 2025 revenue dollar it projected (PostQuantum). That gap is one reason the SEC tightened its SPAC rules.

7. Case studies: nuclear

Small modular reactor developers have used both routes: SPAC mergers since 2022, and in 2026 the sector's largest traditional IPO.

In plain terms: what is an SMR? A small modular reactor is built largely in a factory from standard modules rather than constructed on site as a one-off. Like cars on an assembly line, each unit should get cheaper and faster to build.

X-energy: the largest advanced-nuclear IPO so far

Founded in 2009 in Maryland (IPOScoop), X-energy develops the Xe-100 reactor and makes its own fuel. It priced at $23 against a $16 to $19 range, selling about 44.3 million shares and raising $1.0 billion (Renaissance Capital), for a valuation of about $9.1 billion (Yahoo Finance). It aims to deliver its first reactor in the early 2030s (Yahoo Finance).

Its registration statement published illustrative unit economics: each four-reactor plant is expected to generate about $2.4 to $4.7 billion in revenue over a 60-year life, with the company warning that actual results could differ materially (S-1). Analysts note SMR listings are often the first time such figures go public (Energy Intelligence).

What it shows: a company with no operating reactor raised over $1 billion on customer agreements, in-house fuel and demand for clean power. The price of that access is disclosure: cost and timeline figures it will be measured against for years.

newcleo: from Paris to Nasdaq

Founded in 2021, newcleo develops lead-cooled fast reactors and fuel from recycled nuclear material (Investing.com). It closed its SPAC merger on 21 September and began trading on 22 September 2026 (newcleo 6-K). Existing shareholders rolled over all their equity (Investing.com). The money will fund a non-nuclear demonstrator in Italy and licensing with US and French regulators (Dealroom).

What it shows: the PIPE decided the deal, supplying nearly nine-tenths of the proceeds (section 4). In a SPAC merger, the quality of the PIPE investors matters as much as the SPAC.

Oklo and NuScale: the first movers

NuScale went public through a Spring Valley SPAC in 2022. Oklo followed, closing its merger with AltC on 9 May 2024 and trading on the NYSE from 10 May (SEC filing). The Spring Valley team is now taking fusion developer General Fusion public by the same route (SEC filing).

8. What to look for in a prospectus

A prospectus is where a company must tell the truth about itself in detail. For deep-tech companies, six areas deserve the closest reading.

In plain terms: words carry legal weight. An "error-detected logical qubit" is not a "fault-tolerant" one (Entangled Future). A reactor "design" is not a "licensed" reactor. A good prospectus defines its terms and uses them consistently; a vague one is a warning sign.

9. Risks and trade-offs

Going public brings money and visibility, but also permanent costs and scrutiny.

10. Bottom line

An IPO is a company's first public sale of shares. It swaps private contracts for public law, and companies do it mainly to raise capital on a scale private markets cannot offer. Deep-tech companies need that scale more than most.

2026 showed the model working in two very different industries: two traditional IPOs of over $1 billion each and a string of SPAC mergers, including European companies listing in New York. It also showed what markets reward: precise technical language, honest risk disclosure and realistic projections. Since the SEC's 2024 reform, that is no longer just good practice. It is the law.

Glossary

Sources and notes

Sources are linked where each fact appears. Statutory references: Securities Act of 1933 (15 U.S.C. § 77a et seq.); Securities Exchange Act of 1934 (15 U.S.C. § 78a et seq.); JOBS Act, Pub. L. 112-106 (2012), as inflation-adjusted; SEC Release No. 33-11265 (2024); Regulation (EU) 2024/2809; Directive (EU) 2024/2810; Atomic Energy Act of 1954, Section 103d (42 U.S.C. § 2133(d)).

Data as of 25 September 2026, as reported by the linked sources; figures may have changed since. Examples without a source are hypothetical. The newcleo redemption rate is calculated from two published figures.

This article is general information only. It is not legal, financial or investment advice, nor an offer or recommendation to buy or sell any security.