The quantum computing industry is at a critical inflection point as it transitions from research labs to commercial applications. While a definitive quantum advantage -- where quantum computers decisively outperform classical systems -- has yet to be achieved, the race to reach this milestone is driving significant investment opportunities. According to The Quantum Insider, quantum computing could generate $1 trillion in economic value by 2035, transforming industries such as finance, defense, life sciences, and manufacturing.

At the forefront of this revolution are IonQ (IONQ 0.80%) and Alphabet (GOOG -0.88%) (GOOGL -0.92%), two companies pursuing distinct technological approaches to quantum computing. As this cutting-edge technology reshapes fields ranging from drug discovery to financial modeling, understanding their unique strategies and market positioning is essential for investors looking to capitalize on its potential.

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Below, I'll explore each company's quantum platform to assess which stock offers the best exposure to this transformative innovation.

The case for IonQ

IonQ's competitive position in quantum computing rests on three key advantages. First, the company's trapped-ion technology is experiencing strong commercial traction, particularly in government and defense.

The company's business momentum is reflected in two recent U.S. Air Force Research Lab contracts -- a $54.5 million quantum computing agreement and a new $21.1 million quantum networking project via Qubitekk. These contracts, coupled with a new strategic partnership with General Dynamics, demonstrate growing confidence in IonQ's quantum solutions.

The company's cloud-based quantum computing services represent another key advantage. IonQ makes its quantum computers accessible through major platforms including Amazon, Microsoft, and Google, creating multiple revenue streams while expanding market reach. This quantum-computing-as-a-service (QCaaS) model allows customers to experiment with quantum applications without significant upfront investment.

However, IonQ remains deeply unprofitable as it prioritizes technological advancement over near-term earnings. Last November, the company reported a net loss of $129.6 million in the first nine months of 2024, with an accumulated deficit of $481.7 million. While concerning, these losses reflect heavy investments in achieving higher qubit counts and fidelity-critical milestones for reaching broad quantum advantage.

The case for Alphabet

Alphabet's quantum computing ambitions demonstrate the power of deep technical expertise and resources. The company's latest Willow quantum processor shows remarkable progress, achieving error correction that scales with more qubits -- a crucial milestone known in the industry as "below threshold." This breakthrough suggests Alphabet is making significant strides toward practical quantum computing.

The technical achievements are striking. Willow completed computations in under five minutes that would take today's fastest supercomputers billions of years to solve. While this benchmark doesn't yet have commercial applications, it validates Alphabet's approach to quantum architecture and error correction. Moreover, Alphabet's state-of-the-art fabrication facility in Santa Barbara gives it end-to-end control over the complex manufacturing process.

However, Alphabet's quantum computing efforts represent just one initiative within its vast technology portfolio. The company's recent earnings show strong artificial intelligence (AI) monetization and cloud growth, driving a rather healthy operating margin of 32% in the most recent quarter. While quantum computing could enhance these businesses over the long term, particularly in AI applications, it remains a research-focused investment, rather than a near-term revenue driver.

Which stock is the better quantum computing play?

For investors seeking pure quantum computing exposure, IonQ presents a clearer opportunity, despite its current unprofitability. The company's growing government contracts and strategic partnerships demonstrate commercial validation of its trapped-ion technology, while its cloud-based service model creates multiple paths to revenue growth as the quantum computing market develops.

Alphabet offers a more balanced investment proposition. While its quantum computing breakthroughs are impressive, particularly in error correction, they represent just one component of a diverse technology portfolio.

The tech stock gives investors quantum computing exposure alongside established revenue streams from advertising, cloud services, and artificial intelligence development. However, for investors specifically seeking quantum computing exposure, pure-play alternatives may offer more focused opportunities.