Not IonQ. Not D-Wave. This Magnificent Quantum Computing Stock Is the One to Own for the Long Haul.

Quantum computing could become one of the next great markets to disrupt artificial intelligence (AI). That possibility has sent investors on a quest to find the next Nvidia. Two stocks that have emerged as quantum computing discussions become increasingly popular are IonQ (NYSE: IONQ) and D-Wave Quantum (NASDAQ: QBTS).

Both companies are making respectable technological progress, but investors need to separate exciting promises from a proven business model. Neither IonQ nor D-Wave is profitable, and both must spend heavily to advance product roadmaps whose biggest commercial opportunities are still years away.

Most investors probably don't realize that Alphabet (NASDAQ: GOOGL) (NASDAQ: GOOG) already owns one of the world's most advanced quantum research labs. Unlike the pure plays, Alphabet doesn't need quantum computing to pay off anytime soon to justify its valuation. That's precisely why I think Alphabet is the best quantum computing stock to own for the long run.

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IonQ and D-Wave are exciting... and risky

IonQ's roots are in trapped-ion quantum computers and has recently expanded into networking, sensing, and security. The company's acquisition of SkyWater also gives IonQ exposure to semiconductor manufacturing capabilities as it tries to build a vertically integrated quantum platform.

The company's growth is impressive. During the second quarter, revenue surged 287% to $80 million and management increased its 2026 revenue forecast to between $450 million and $460 million. With that said, IonQ also posted a $120 million adjusted EBITDA loss during the quarter.

D-Wave is taking another approach. The company specializes in quantum annealing, a technology designed to solve optimization problems involving logistics, scheduling, and manufacturing.

The problem with investing in IonQ or D-Wave is that investors are paying a premium today for businesses that remain largely unproven. Quantum computing requires enormous research and development (R&D) spending. Until these companies can generate sufficient cash to fund those investments, acquisitions and R&D will require additional capital. That creates the possibility of future debt raises or stock dilution.

IONQ PS Ratio data by YCharts

Google already achieved a quantum breakthrough

Alphabet has been researching quantum computing for more than a decade through Google Quantum AI. The company's biggest recent breakthrough revolves around a chip called Willow. Google's Willow quantum chip has demonstrated two important achievements to date.

First, Google proved that errors could decline exponentially as additional qubits are added. This is a critical step toward building larger, error-corrected quantum computers. Second, Willow completed a computation in less than five minutes that Google estimates would take one of today's fastest supercomputers 10 septillion years to solve.

It's important to note that these breakthroughs don't necessarily make quantum a major part of Alphabet's business right now. Alphabet's current AI roadmap revolves around Gemini, Google Cloud, Search, advertising, custom silicon, autonomous driving through Waymo, and data center investments.

The key is to imagine how quantum computing could eventually fit into Alphabet's existing AI ecosystem. Google Cloud could provide businesses access to quantum computing just as it provides access to its custom chips, called Tensor Processing Units (TPUs). Gemini could help developers and researchers interact with quantum systems and design new algorithms. Meanwhile, quantum computers could potentially accelerate Google's presence in materials science, chemistry, drug discovery, optimization, and machine learning.

Alphabet gives investors quantum upside without the hefty price tag

Alphabet doesn't need to build an entirely new distribution network for quantum computing since it already has one through Search, YouTube, advertising, cloud computing, AI models, custom chips, and autonomous vehicles.

Alphabet currently trades at a forward price-to-earnings (P/E) ratio around 29. While that is not cheap in an absolute sense, it's hardly an outrageous valuation for a company with Alphabet's competitive advantages and expanding AI opportunities. More importantly, investors aren't being asked to justify a valuation that solely rests on quantum computing becoming a major opportunity.

GOOGL PE Ratio (Forward) data by YCharts

IonQ and D-Wave could deliver multibagger returns if they emerge as quantum computing winners. But right now, both companies carry substantial technological, financial, and dilution risk. Alphabet gives investors something different: a world-class AI company with a potentially asymmetric quantum opportunity sitting quietly in the background. That's why Alphabet -- not IonQ or D-Wave -- is the quantum computing stock I'd feel most comfortable owning for the next decade.

Adam Spatacco has positions in Alphabet and Nvidia. The Motley Fool has positions in and recommends Alphabet, IonQ, and Nvidia. The Motley Fool has a disclosure policy.