Quantum computing is a promising field with massive long-term potential, but it is still in its early commercialization phase. This can make investing in quantum computing businesses a high-risk, high-reward proposition suitable for only a small portion of a diversified portfolio.
Investors can approach this sector in two primary ways: through established tech giants or pure-play start-ups. The former offer a more stable entry point, as quantum computing is only a small part of their diversified operations. This approach can limit the impact of quantum-specific volatility on your overall investment.
On the other hand, pure-play quantum computing stocks can be highly speculative, early-stage companies whose stock prices are often volatile and tied to technological breakthroughs and future potential rather than current profits, but which could deliver higher returns if successful.
On today's list, I've included one quantum computing stock from each bucket for long-term investors to consider. Let's dive right in.
Image source: Getty Images.
1. Alphabet
Alphabet (GOOGL 1.43%) (GOOG 1.34%), through its Google Quantum AI division, is a leader in developing quantum computing technology focused on creating a large-scale, error-corrected quantum computer for solving problems currently impossible for classical supercomputers. Its recent work has led to significant breakthroughs, including the Willow quantum chip.
The Willow chip, unveiled in late 2024, has achieved two major milestones. First, it can significantly reduce error rates as more qubits (quantum bits, the basic units of quantum information) are added, which is a crucial step for building a scalable and reliable quantum computer. In October 2025, Google Quantum AI announced a breakthrough algorithm called Quantum Echoes run on the Willow hardware that generated a calculation demonstrably faster (13,000x) than any classical supercomputer.
The algorithm also achieved verifiable quantum advantage, which means it is repeatable and can be checked by other quantum systems. The work on the Quantum Echoes algorithm is a major step toward practical applications.
Potential uses range from drug discovery and medicine to materials science. Google Quantum AI is pursuing a six-milestone roadmap to build a large error-corrected quantum computer with a goal of 1 million qubits. The division regularly collaborates with universities and national labs to provide access to their processors via the Google Cloud platform.
NASDAQ: GOOG
Key Data Points
Unlike smaller pure-play quantum computing companies that require constant fundraising, Alphabet can leverage immense profits from its core advertising and Google Cloud businesses to fund decades of research without pressure for immediate commercial viability. A key challenge in quantum computing is error correction. The Willow chip was designed to exponentially reduce errors as qubits are added, which is a major technical advance over competitors.
The company's vision includes integrating future quantum computing capabilities into its existing AI ecosystem and Google Cloud platforms. In the third quarter, Alphabet's revenue grew 16% year over year to $102.3 billion, and net income climbed 33% to about $35 billion. The company is also a leader in artificial intelligence (AI), which is driving real business results and driving heavy investment in data centers and custom chips.
Alphabet maintains a virtually unassailable financial position, with a strong balance sheet including $98.5 billion in cash and marketable securities, and low debt too. Long-term investors who want to add wealth-building stocks to their portfolio should certainly consider taking a position in this business.
2. IonQ
IonQ (IONQ 2.33%) IonQ is a leading pure-play quantum computing company that utilizes trapped-ion technology to build high-performance quantum systems. Unlike competitors like Alphabet and International Business Machines that primarily use superconducting qubits, IonQ's approach leverages naturally occurring, identical trapped ions as qubits.
By using naturally stable atoms that are isolated in a vacuum, IonQ's qubits are less susceptible to environmental noise and decoherence. In short, this can lead to fewer errors and more reliable results.
In October 2025, IonQ achieved 99.99% two-qubit gate fidelity, a critical industry benchmark that essentially means its quantum computers can perform complex operations with extremely high accuracy. Every qubit in an IonQ system can directly interact with any other qubit. This slashes the computational overhead and errors required to move data between qubits.
IonQ is actively collaborating with partners to solve complex problems in several sectors. The company is working on accelerated drug development workflows with companies like AstraZeneca and Nvidia, it's partnered with Hyundai to use quantum AI for image recognition in self-driving cars, and even collaborated with Airbus to optimize high-complexity cargo loading problems.
NYSE: IONQ
Key Data Points
IonQ operates with an evolving business model that's designed to monetize its proprietary trapped ion technology through three primary avenues. One is through QCaaS, or Quantum Computing as a Service, a cloud-based model that lets major cloud providers like Amazon, Microsoft, and Google access quantum hardware, software, and tools remotely, much like traditional cloud services.
Another revenue source involves partnering with government agencies and enterprises for specialized quantum applications. IonQ is also expanding into quantum networking, sensing, and security after strategic 2025 acquisitions like Oxford Ionics and Vector Atomic.
In Q3, IonQ's revenue surged 222% year over year to $39.9 million. The company reported a substantial GAAP net loss of $1.1 billion, largely due to non-cash charges related to warrant liabilities and acquisition costs. Following a $2 billion equity offering in October, IonQ holds a pro forma cash balance of $3.5 billion and carries zero long-term debt.
IonQ could enrich long-term investors if it successfully transitions from a high-growth speculative play to a dominant utility in the quantum era. It is currently the only pure-play public quantum company with triple-digit annual revenue growth and widespread cloud integration.
