Quantum computing has been on the minds of the technology sector for decades, mainly due to its potential to solve complex problems that would take traditional computers orders of magnitude more time.
But despite this great promise, private investment into the companies developing quantum technology has remained marginal compared to other segments of the tech space.
Analysis from McKinsey shows more than 300 global companies have adopted quantum computing in some fashion, with evidence that despite its infancy, real-world solutions are being tested, developed, and moving into commercial deployment.
This adoption has fuelled a market that is now valued at US$1.9 billion in 2025 and projected to exceed US$4 billion by 2028, according to a report released by the Quantum Economic Development Consortium.
Crucially, investors are recognising quantum computing’s commercial promise, with investment in quantum technology start-ups reaching US$12.6 billion in 2025, more than six times higher than the previous year.
“What changed in 2025 was the arrival of the proof points institutional investors underwrite against: early revenue, strategic validation, and more concrete technical timelines,” Lepske explained.
Throughout 2024 the case still rested largely on research promise, but in 2025 the sector started to look like an early market.
In addition to an explosion in revenue, Lepske thinks that several factors have boosted quantum computing’s attractiveness to venture capital.
She points to the example of IonQ’s ~US$1.075 billion acquisition of Oxford Ionics as a signal that incumbents will pay for specific capabilities, not just optionality, as well as technical roadmaps becoming concrete enough to price.
“Credible fault-tolerance milestones let investors attach timelines to returns rather than betting on open-ended research,” she summarises. “Institutions deployed more not because quantum is suddenly proven, but because 2025 finally produced enough revenue, validation and roadmap clarity to underwrite longer-duration bets.”
As for the development of this trend heading into 2026, Lepske only expects more momentum for private capital entering the space.
The numbers from previous years more than support this conclusion.
According to McKinsey, in 2024, one-third of investment came from public sources, compared with just 3% in 2025.
Private Capital’s increasing market share of the funding for Quantum companies has a significant impact on the future of the market.
“Private capital is a stronger signal of commercial conviction than grants,” Lepske says. “Grants fund promise, but private money is deployed in the expectation of eventual customer demand and a return on the initial investment.”
A shift towards quantum company’s sourcing funding from private money means investors now believe there’s a market, not just a research agenda.
It also means the industry will now be expected to move faster, with the private capital available accelerates hiring, partnerships, acquisitions and product roadmaps in ways Lepske says that grant cycles just aren’t built for.
“There is also a strategic reason behind it. Governments are trying to seed ecosystems, but private capital is what funds the scaling phase,” she explains.
While still a fraction of AI’s investment volumes, suggest quantum has moved well beyond its experimental phase.
Public markets have reinforced quantum’s growth narrative during 2026, with several transactions closing at valuations that would have read as mightily ambitious just a few years ago.
In March, Xanadu completed its merger with Crane Harbor, listing on Nasdaq and the Toronto Stock Exchange at a valuation of roughly US$3.1 billion. Three months later, Quantinuum completed the largest quantum IPO to date, raising US$1.68 billion at an implied valuation approaching US$15.7 billion. Europe’s first listed quantum company, IQM, followed in July through its merger with Real Asset Acquisition Corp., debuting with a valuation of approximately US$1.9 billion.
For an industry that only recently struggled to convince investors it had a commercial future, three sizeable public listings within four months represent a notable milestone.
“Three public-market entries in four months pull in a pool of capital that private rounds alone couldn’t, which steepens rather than flattens the near-term curve,” Lepske concludes from these recent milestones.
However, while the signs of a blooming market are impossible to ignore, it’s also true that quantum is yet to have its “ChatGPT moment” – an undeniable overnight change in the perception of the commercial application of a frontier technology.
Unlike AI, the commercial promise of which has become difficult to dispute given usage stats for the most popular models, quantum computing is still searching for the breakthrough application that convinces mainstream enterprise customers to buy repeatedly rather than experiment.
That uncertainty was reflected in the public market debuts. Quantinuum finished broadly flat on its first day of trading, while IQM closed below its issue price after warning investors in its prospectus that widespread commercial adoption “may never occur”.
“The investment curve is the one most exposed to sentiment,” Lepske says. “A high-profile technical miss or a broad risk-off market could flatten funding quickly even while adoption keeps grinding upward.”
Investors therefore face a more nuanced question than whether quantum computers will eventually work. Increasingly, the issue is how quickly commercial evidence accumulates.
Lepske argues that investors should pay less attention to laboratory announcements than to business metrics that are difficult to manufacture.
The strongest indicators will be recurring enterprise revenue, customers renewing contracts beyond pilot programmes and demonstrable examples where quantum computing delivers a measurable advantage over classical systems in cost, speed, accuracy or strategic value.
Strategic acquisitions and partnerships will also remain important because they demonstrate that incumbents are willing to pay for specific technological capabilities rather than speculative future potential.
Technical milestones matter too, particularly as companies pursue fault-tolerant quantum systems.
But ultimately, Lepske believes the defining milestone will not come from a scientific journal.
“The single strongest signal is commercial, not technical,” she says. “A customer saying they bought it because it changed a business process and generated value, not because it was a research experiment.”
That, she argues, will constitute quantum computing’s equivalent of artificial intelligence’s ChatGPT moment.
Rather than one spectacular technical breakthrough, quantum’s inflection point will arrive when fault-tolerant systems become cloud-accessible and repeatedly deliver measurable value in commercially important sectors such as chemistry, advanced materials and optimisation.
Cloud infrastructure will be central to that transition. QuEra’s planned Libra system, scheduled to become available through AWS Braket, represents an important step towards democratising access to fault-tolerant quantum hardware. But Lepske believes the larger opportunity lies beyond Libra.
In June, QuEra unveiled plans for a next-generation “gigaquop-class” system targeting more than 1,000 logical qubits, over 20,000 physical qubits and approximately one billion reliable logical operations by 2028-29.
If delivered on schedule, systems operating at that scale could support commercially valuable workloads that remain beyond the reach of classical computing.
“The AI moment wasn’t a benchmark,” Lepske says. “It was usefulness becoming undeniable at scale. Quantum’s equivalent is the same: repeatable, commercially paid wins in markets where the classical alternative is visibly outmatched.”
