Deep Tech Needs Patient Capital: How We Evaluate 10-Year Returns at the Seed Stage

By Curevstone Capital Research Team · February 2025 · 11 min read

Venture capital, as it is conventionally practiced, was built around a cadence that deep tech companies fundamentally cannot honor. The typical VC fund has a ten-year lifespan, with most investments expected to return capital within five to seven years. A software startup that ships a product in six months, hits $1M ARR in twelve months, and scales to $10M ARR in three years fits cleanly inside that model. A company developing fault-tolerant quantum computing hardware, a commercial nuclear fusion reactor, or grid-scale iron-air batteries does not.

And yet, the potential returns from deep tech investing — when the technology works, when the market timing is right, and when the team can execute across a decade-long development curve — are categorically different from anything available in software. We are talking about companies that could be worth tens or hundreds of billions of dollars, that could restructure entire industries, and that could solve problems that software alone is simply not capable of addressing. Climate change cannot be fixed with a SaaS dashboard. Quantum computing advantage cannot be achieved with a Python wrapper. The physical world requires physical solutions.

At Curevstone Capital, we have developed a framework for evaluating deep tech investments at the seed stage that takes the long time horizons seriously — not as a bug to be managed, but as a feature to be underwritten. This post explains how we think about 10-year return profiles, why patient capital is not just a nice-to-have but a structural prerequisite for deep tech investing done well, and what the case studies of PsiQuantum, Commonwealth Fusion Systems, and Form Energy teach us about the anatomy of a generational deep tech bet.

The Mismatch Between Deep Tech and Conventional Venture

The tension between deep tech development timelines and venture fund mechanics is well-documented, but it is worth being precise about what the mismatch actually is — because the solution depends on understanding the problem clearly.

Deep tech companies typically go through three distinct phases before they generate meaningful commercial revenue. The first is the scientific validation phase: demonstrating that the underlying physical or chemical mechanism works at all, even at small scale or in a laboratory environment. The second is the engineering scale-up phase: translating a scientific proof-of-concept into a manufacturable, reliable, cost-competitive product. The third is the commercial deployment phase: building the sales channels, supply chains, and service infrastructure required to reach customers at scale.

Each of these phases can take years and requires capital with a very different risk tolerance. The scientific validation phase is the riskiest — there is genuine technical uncertainty about whether the thing will work — but it is also the phase where seed-stage investors can enter at the lowest valuations and with the most equity for a given dollar invested. The engineering scale-up phase requires large amounts of capital to build prototype systems, manufacturing lines, and testing infrastructure — this is where Series A and B investors typically participate. The commercial deployment phase, finally, is where growth-stage capital becomes relevant.

A seed investor in deep tech is, in effect, making a bet on all three phases. They are writing a check when technical risk is highest, when the timeline to returns is longest, and when the path from where the company is to where it needs to be requires a coherent 10-year roadmap, not an 18-month sprint. This requires a fundamentally different mental model than software investing.

"Patient capital is not passive capital. It is active, engaged, and deeply informed — but calibrated to the timeline of the technology, not the preference of the fund."

Case Study: PsiQuantum and the Quantum Computing Long Game

PsiQuantum is perhaps the most audacious deep tech bet of the current decade. The company, founded by quantum photonics pioneers from Bristol and Stanford, has raised over $665 million to pursue a single, enormously ambitious goal: building the world's first fault-tolerant quantum computer using photons and standard silicon semiconductor manufacturing processes.

The PsiQuantum thesis rests on a profound insight that is simultaneously a technical bet and a manufacturing bet. While most quantum computing companies are building superconducting qubit systems that require near-absolute-zero cooling and custom fabrication processes, PsiQuantum has chosen photonic qubits that can — in principle — be manufactured at scale using existing silicon foundry infrastructure from companies like GlobalFoundries. If this bet is correct, PsiQuantum can scale to the million-qubit counts required for fault-tolerant computation faster than any superconducting approach, because they can leverage $10 trillion in existing semiconductor manufacturing infrastructure.

This is not a company that will generate commercial revenue in three years. It may not generate meaningful commercial revenue in five. The timeline to useful fault-tolerant quantum computation is, by PsiQuantum's own estimates, in the latter half of this decade — and that assumes everything goes to plan. For an investor with a five-year return horizon, this is simply not investable. For an investor with a ten-year horizon and conviction in the team and approach, the calculus is entirely different.

At the seed stage, the question we ask about a company like PsiQuantum — or a company at the PsiQuantum stage of development — is not "when will this make money?" It is: "Is the core technical thesis defensible? Is the team uniquely qualified to execute it? Is the market potential, if the thesis is correct, large enough to justify the time and capital required?" For PsiQuantum, the answers to all three are affirmative, which explains why it has attracted capital from sophisticated institutional investors including Baillie Gifford and the governments of Australia and Canada.

The lesson for seed-stage deep tech investing: quantum computing companies founded today will be racing to demonstrate fault tolerance while PsiQuantum is racing to demonstrate scale-manufacturing. The seed investor who bets on a quantum startup today is not buying a current product — they are buying an option on a technical roadmap and a team. Evaluating that option requires a different analytical toolkit than evaluating a SaaS company's ARR growth.

Case Study: Commonwealth Fusion Systems and the Fusion Energy Bet

Commonwealth Fusion Systems has raised over $1.8 billion — making it the best-funded private fusion company in the world — on the basis of a technical milestone that was, until recently, considered impossible on a commercial timeline: demonstrating high-temperature superconducting (HTS) magnets capable of generating the 20-tesla magnetic fields required for compact fusion reactors.

In September 2021, CFS demonstrated exactly that. Their HTS magnets achieved 20 teslas, validating the core technical premise of their entire roadmap. It was, as observers noted at the time, not just a scientific milestone but a commercial one — it proved that the timeline to a working fusion pilot plant (SPARC) and ultimately a commercial plant (ARC) was plausible within the decade.

The CFS story illustrates one of the most important dynamics in deep tech investing: the relationship between technical milestones and capital-raising leverage. Before the magnet demonstration, CFS was a company with a compelling thesis and a world-class team from MIT's Plasma Science and Fusion Center. After the demonstration, it was a company with proof of the critical path. The capital-raising power of that demonstration was enormous — it enabled a $1.8 billion raise that simply would not have been possible without the technical validation.

For a seed investor, this dynamic creates a specific opportunity structure: invest before the milestone, at the valuation that reflects the technical uncertainty, and let the milestone carry the valuation step-function up. This requires the ability to identify teams capable of reaching those milestones — which in turn requires deep technical diligence of the kind that most generalist VCs cannot perform effectively.

The broader implication for deep tech investing is about the nature of risk. Nuclear fusion is not a novel scientific concept — it has been understood for decades. The risk in fusion investing is not whether fusion is physically possible; it demonstrably is. The risk is engineering: can this team solve the engineering challenges required to make fusion commercially viable, within the capital available, on a timeline that matters? CFS's answer to that question has been, so far, extremely impressive.

Case Study: Form Energy and the Grid Storage Problem

Form Energy's bet is, in some ways, the most grounded of the three cases in this post — because the problem it is solving is not speculative. The intermittency of renewable energy is a real, present, and growing challenge for electrical grids worldwide. Solar panels generate electricity when the sun shines; wind turbines generate electricity when the wind blows. Neither of these facts aligns reliably with when industrial and residential users need power. The solution to this mismatch is storage — and existing battery technologies, dominated by lithium-ion, are capable of storing energy for four to eight hours but are not economically viable for the multi-day storage that a truly renewable-powered grid requires.

Form Energy's iron-air batteries use a remarkably simple electrochemical mechanism — rusting and un-rusting iron — to store energy at a cost that the company projects will reach approximately $20 per kilowatt-hour. This is roughly one-tenth the cost of lithium-ion at equivalent scale, and it enables storage durations of 100 hours or more. The raw materials — iron, air, water — are abundant, non-toxic, and globally distributed. The manufacturing process, unlike lithium-ion, does not depend on rare earth minerals with concentrated supply chains.

Form Energy has raised over $450 million and is currently building out its first commercial manufacturing facility. The company has offtake agreements with utilities including Georgia Power and Minnesota Power, which represent the first commercial validation of its technology in production grid environments. But Form Energy is not yet generating meaningful revenue at scale — it is still in the engineering scale-up phase, transitioning from validated prototypes to the kind of manufacturing yields and cost structures that make the commercial business model work.

For deep tech investors, Form Energy illustrates a crucial distinction: the difference between technical risk and execution risk. The science of iron-air batteries is not in dispute — it is well-established electrochemistry. The risk in Form Energy is whether the company can build a manufacturable, reliable, cost-competitive product at the pace and scale required to capture the grid storage market before alternatives emerge. That is an execution challenge, not a scientific one, and it requires a different kind of diligence to assess.

Our Framework for Evaluating 10-Year Deep Tech Returns

The framework above represents the distillation of how we think about deep tech seed investments at Curevstone. Each dimension is a lens, not a checkbox — the art of deep tech investing is in weighing these factors against each other and building a probabilistic view of the path to the return scenario.

The Capital Intensity Challenge and How Patient Capital Solves It

One of the most underappreciated challenges in deep tech investing is the capital intensity curve: the fact that the capital required to advance a deep tech company from seed to commercial stage is often two or three orders of magnitude larger than for a software company at the same stage. PsiQuantum has raised $665 million. Commonwealth Fusion has raised $1.8 billion. Form Energy has raised $450 million. None of these totals were imaginable at the seed stage.

This creates a specific challenge for seed investors: the dilution from subsequent funding rounds can dramatically reduce the seed investor's ownership by the time returns are realized. A seed investor who owns 10% of a deep tech company at seed may own 2-3% by the time the company reaches commercialization, after a decade of large capital raises. For the return math to work, the exit valuation needs to be large enough to make even that diluted ownership position worthwhile.

This is why deep tech investing, done properly, requires targeting companies with potential exit valuations in the many billions of dollars. A company that reaches $500M in valuation after ten years of development and $1B in capital raised may generate poor returns for early investors. A company that reaches $10B — or $50B, as some of these deep tech categories could support — generates extraordinary returns even on a highly diluted seed position.

The practical implication for how we structure deep tech investments at Curevstone is that we look for minimum $10B terminal valuation potential when the thesis is fully realized. This is a high bar — it means we are not interested in deep tech companies building solutions for niche markets, however impressive the technology. We want deep tech companies solving problems at civilizational scale: clean energy, quantum computation, advanced materials, precision medicine, and next-generation computing architectures.

Why the Seed Stage Is Still the Right Entry Point

Given all of the complexity and risk described above, one might reasonably ask: why invest in deep tech at the seed stage at all? Why not wait for technical validation, invest at a higher valuation with less binary risk, and still capture a meaningful portion of the upside?

The answer lies in the economics of information. At the seed stage, the market has not yet priced in the full potential of a team and technical approach that have not yet produced public results. The investor who can perform deep technical diligence — who can assess whether the team's approach is scientifically sound, whether the milestone roadmap is credible, and whether the market opportunity is as large as the team believes — has a fundamental information advantage over the market.

By the time a deep tech company demonstrates its first major technical milestone, that information is public. Valuations step up dramatically. The easy money has already been made. CFS's valuation after the 20-tesla magnet demonstration was substantially higher than it was before. Form Energy's valuation after its first utility partnership announcement reflected the commercial traction that seed investors were betting on. The seed investor who can evaluate the potential before these milestones captures the maximum return.

At Curevstone, we build the technical evaluation capacity to make these judgments. Our team includes advisors and network connections spanning quantum physics, materials science, electrochemistry, and nuclear engineering — precisely because evaluating deep tech requires subject matter expertise that cannot be borrowed from a generalist investment framework.

The Policy Tailwind: Deep Tech Is Having a Moment

One development that has materially improved the deep tech investment environment over the past several years is the convergence of government policy around strategic technology categories. The CHIPS Act, the Inflation Reduction Act, the Department of Energy's loan programs, and equivalent policy frameworks in the EU, UK, Australia, and Japan have created a policy environment that is actively de-risking deep tech investment in ways that were not available to the previous generation of deep tech investors.

Form Energy, for example, has benefited from IRA manufacturing credits that make grid-scale battery production in the United States financially viable. CFS has received support from the U.S. Department of Energy's fusion program. PsiQuantum has received commitments from the governments of Australia and Canada that include both capital and access to advanced manufacturing infrastructure.

For a seed-stage deep tech investor, these policy tailwinds are a meaningful input into the return calculation. A company that can leverage non-dilutive government capital — grants, loans, tax credits, manufacturing incentives — requires less dilutive private capital to reach commercialization, which means better outcomes for early equity holders. Policy risk is also a real input, of course: programs can be modified, delayed, or cancelled. But the broad direction of policy across major economies is clearly supportive of domestic deep tech development, and that is a structural tailwind that is likely to persist.

"The best deep tech bets are ones where private capital and patient public policy are rowing in the same direction — toward the same technological destination, on a timeline that both can live with."

Building a Deep Tech Portfolio at the Seed Stage

Deep tech investing at the seed stage requires portfolio construction discipline that is specifically calibrated for binary outcomes and long timelines. A portfolio of ten deep tech seed investments, in which two or three return massive multiples and the remaining six or seven return zero or modest amounts, can still generate outstanding fund-level returns if the winners are large enough. This is the power law of deep tech investing: a single company that reaches $20B in value can more than offset the entire portfolio's losses.

At Curevstone Capital, we structure our deep tech portfolio to include diversification across technology verticals — quantum computing, energy storage, advanced manufacturing, biotechnology, climate technology — while maintaining concentration in our highest-conviction positions. We do not believe in betting on every deep tech subcategory. We believe in doing enough diligence to have strong opinions, and then backing those opinions with meaningful checks.

We also believe in staying close to our deep tech companies across their development lifecycle. The role of the seed investor in a deep tech company is not just capital provision — it is network access, talent introductions, downstream investor relationships, and strategic guidance as the company navigates the transition from scientific proof-of-concept to commercial product. The most successful deep tech investors are not hands-off check-writers; they are long-term partners who understand the technology deeply enough to add value at every stage.

Conclusion: The Patience Premium

Patient capital is not a compromise. It is a strategy. In deep tech, the investors who are willing to operate on 10-year timelines — who do not need quarterly progress reports, who understand that technical development is non-linear, and who can hold their positions through the inevitable setbacks and recalibrations that every hard technology company experiences — have access to investment opportunities that are simply not available to investors with shorter time horizons.

PsiQuantum, Commonwealth Fusion Systems, and Form Energy are not unicorns because they got lucky. They attracted patient capital from investors who understood the technology, trusted the teams, and were willing to wait for the inflection points that would validate the thesis. That capital — and that patience — is what enabled each company to survive the long development arc that precedes commercial viability in deep tech.

At Curevstone Capital, we are building a portfolio of companies that we expect to be defining players in their respective categories by the mid-2030s. Some of them will fail. Some will take longer than expected. A small number will do something genuinely extraordinary — and the returns from that small number will justify everything.

That is what patient capital means in practice. Not passivity, not tolerance for mediocrity, not willingness to let struggling companies limp along indefinitely. It means calibrating your expectations, your portfolio construction, and your relationship with founders to the actual rhythm of the technology — not the rhythm of the fund cycle. That is the kind of capital deep tech deserves, and it is the kind of investor we aspire to be.

If you are building a company in quantum computing, advanced energy, novel materials, or any other hard technology category, and you are looking for a seed partner who has done the homework — we would love to hear from you.