The Stack: Quantum Computing

The Stack: Quantum Computing

The Surface

On June 4th, Quantinuum IPO on NASDAQ, bringing attention back to the quantum computing market, one which has laid dormant for nearly a year following an introduction to the public scene in mid-2025. Quantinuum managed to raise 1.68B, and closed nearly flat the day of its IPO. Nearly a month and a half later, it continues to stay stable, as recent losses have wiped out a run towards the end of June.

The introduction of Quantinuum lands on top of a year where the big 4 new exciting quantum computing companies captured the headlines, namely IONQ, QBTS, RGTI, and QUBT have run hard. These companies, over the years, have seen a similar pattern as Quantinuum did since it’s IPO, as they surged in 2025 before falling back to pre-surge numbers, holding stable ever since until a surge along with the Quantinuum IPO that has since then died down once again.

These companies, while holding complicated technology, are financially rather simple: they are pre-revenue names carrying tens of billions of market capitalization based on the promise of quantum computing becoming the next generation of computing power, with fault tolerant machines that run faster and cleaner than conventional computers. The stack aims to dive into the realm of quantum computing to answer a single question: If the computer itself is still years from paying for itself, where in this supply chain does the real risk, and thus, reward, actually sit?

The Chain

While these new and exciting names have been dominating headlines in computing, the industry as a whole is still reliant and popularized by traditional giants, household names such as IBM and Google. A quick overview can be summarized as such:

1. Algorithms & End applications — drug discovery, optimization, cryptography
2. Quantum Computers — IONQ, QUBT, RGTI, QBTS, Quantinuum and IBM,Google,Intel labs.
3. Control and Measurement Electronics — signal generation, readout, and the move to cryo-CMOS
4. Cryogenics — the millikelvin environment
5. Qubit Fabrication — chip building
6. Specialty Isotopes — helium-3 for cooling, silicon-28 for spin qubits, niobium for superconducting circuits

The potential end applications of quantum computing, things that would genuinely improve the day to day lives of people, all rely on a chain of relatively unknown ideas and names to the public, most of which are privately held companies and patents of technologies that these new era Quantum computing companies rely on.

The Chokepoints

The computing supply chain is held hostage, in a sense, by a few layers of development.

• Quantum Computers: The actual quantum computing development may be the most public part of the chain, and it may also be the most competitive. Firms creating computing power are usually publicly traded, or subsidiaries of major firms. There is no horizontal integration here, as this is the place that competes for market attention and aims to battle for the best developments above them.
• Cryo-CMOS Control: As qubit counts scale, room-temperature wiring breaks, controlling the environments necessary for these computers to scale and work is key for the industry development into commercial use in the future. Like AI data centers, these will become the key discussion point as Quantum truly comes into fruition.
• Specialty Isotopes: A near-monopoly by privately held firms that feeds specialized isotopes for quantum firms like helium-3 and silicon-28. There is a structural annual deficit, and prices in the thousands of dollars per liter. The materials makers behind the isotopes have immense power over the markets below it.

The Basket

While there are buyable options at every point of the quantum computing supply chain, the specialized private companies near the top often outcompete the multipurpose public companies.

• Quantum Computing:
  • Specialized: IONQ, QNT, RGTI, QBTS, QUBT
  • Traditional: IBM, GOOGL, MSFT, INTC, NVDA
• Cooling:
  • Public: OXIG.L / OXINF
  • Private: Bluefors, Maybell, Leiden, Kiutra
• Control and Measurement:
  • Public: KEYS, INTC
  • Private: SEEQC, Quantum Machines, Zurich, Qblox
• Qubit Fabrication:
  • Public: ASPI, FORM, GFS, STM, SKYT
  • Private: imec, Diraq, SQC

Bluefors, SEEQC, Interlune (He-3) are the totally locked off private companies that hold the largest stakes in the industry. These should be watched extremely keenly, either for collaborations and partnerships with quantum computing firms down the supply chain, or for possible IPOs themselves.

Why Now

With the recent reintroduction of Quantum into the public eye, there is no better time than now to understand the quantum supply chain, so whenever it comes into full fruition in the future, there is a basic understanding already of the ins and outs of quantum creation, reliance, and expansion. Recent events suggest that the day of fruition may be closer than one may think.

• Quantinuum's Jun 4 IPO: A major milestone as another major Quantum Computing player joins the public trading competition.
• US $2B Sector Build-Out: Government money flowing into domestic quantum supply chains.
• Error-correction Milestones: IBM's fault-tolerant roadmap and Google's below-threshold results moving "someday" toward "scheduled”

The Month Ahead

In the month ahead, each of the chokepoints will be covered in its specialty article.

• Quantum Computing
  • Quantum computers that are important right now to the current competition
  • The “product” of the industry that can be carried over into other industries (e.g. forensics, pharmaceuticals, etc.)
• Cryo-CMOS Control
  • Cryo-CMOS is key to the future scaling once the product is expanded and improved
  • Vital as the AI data centers of quantum computing that control scaling as the product is commercialized
• Specialty Isotopes
  • The basic elements that allow quantum computing to exist
  • Controls ability for these quantum computers to expand in capacity with both availability and cost concerns

The market is closely watching the computers, but it’s important to go a step ahead and analyze the private parts of the chain in order to understand the significance of each move that these headlining firms make in relation to their ability to create, commercialize, and scale.