IonQ or Rigetti: Who Wins From Microsoft's Cloud Quantum Push?

Quantum computing just got a major vote of confidence from one of the world’s most influential tech leaders. On Microsoft’s MSFT fourth-quarter fiscal 2025 earnings call, CEO Satya Nadella declared quantum to be “the next big accelerator in the cloud,” highlighting the company’s first operational deployment of a Level 2 quantum computer with Atom Computing.

The statement fueled fresh enthusiasm around pure-play quantum firms like IonQ IONQ and Rigetti Computing RGTI. IonQ, with its trapped-ion approach strengthened by acquisitions such as Oxford Ionics and Rigetti, with its superconducting modular design, both stand at the center of the race to scale quantum for the cloud. With Microsoft projecting quantum as integral to the next decade of hyperscaler growth, the question for investors is clear: which of these hardware innovators is better positioned to capture that momentum?

Let's find out.

Over the past six months, shares of Rigetti have gained 80.2% compared to IonQ’s 55.2% growth. Both stocks have strongly outperformed the S&P 500’s 11.3% growth during this period.

Key Growth Drivers of IONQ

Strong Capital Position: IonQ secured the largest single institutional investment in the quantum industry’s history, a $1 billion equity raise at a premium from an affiliate of Susquehanna. This brought its cash balance to $1.6 billion as of July 2025, making IonQ the most well-capitalized pure-play quantum company. When scaling hardware requires multi-year R&D funding, this fund creation seems to be a vital approach.

Expanding Global Ecosystem and Commercial Adoption: IonQ is securing both national and enterprise ecosystems through strategic deal wins such as partnerships with South Korea’s KISTI, Japan’s AIST G-QuAT and a $22 million U.S. contract with EPB to build the first commercial quantum hub. On the enterprise side, its collaboration with AstraZeneca, AWS and NVIDIA NVDA delivered a 20x speedup in drug discovery workflows, underscoring real-world quantum advantage. Together, these government alliances and commercial breakthroughs strengthen IonQ’s position in the global quantum space.

Technology Roadmap and Vertical Integration: Through acquisitions like Oxford Ionics, Lightsynq, Capella and ID Quantique, IonQ is building a vertically integrated platform spanning computing, networking and security. The roadmap targets 800 logical qubits by 2027 and 80,000 by 2030, enabled by photonic interconnects for modular scaling.

Key Growth Drivers of RGTI

Strengthened Balance Sheet for R&D Acceleration: Rigetti raised $350 million in the second quarter of 2025, boosting its cash position to $571.6 million with no debt. This provides ample runway to fund its 3-4 year roadmap toward 1,000+ qubits and 99.9% fidelity that are essential for quantum advantage. The company remains focused on channeling capital into R&D while keeping options for M&A if opportunities arise.

Rigetti Chiplet on Microsoft Azure: Rigetti is progressing with its proprietary chiplet approach, validated by the launch of Cepheus-1-36Q, the industry’s largest multichip quantum computer, deployed on Rigetti QCS and soon on Microsoft Azure. Cepheus-1 has achieved 99.5% median two-qubit fidelity and a 2x error-rate reduction versus its predecessor. With a clear roadmap to deliver a 100+ qubit chiplet-based system by year-end 2025, Rigetti is positioning superconducting qubits as the fastest to quantum advantage.

Strategic Partnerships and Government Contracts: Rigetti continues to engage in government and defense-backed quantum programs, including collaborations with the U.K.’s National Quantum Computing Centre and the U.S. DARPA QBI initiative, where it hopes to advance to Phase 2 later this year. Its hardware partnership with Quanta and continued support from DOE, DoD and allied agencies provide both near-term revenue and validation of its chiplet-based modular design as a viable path to fault-tolerant quantum computing.

2025 Earnings Estimates More Favorable for RGTI

Earnings estimates for IONQ have declined from a loss of 47 cents per share to a loss of 66 cents per share for 2025 over the past 30 days. This, however, signifies growth of 57.7% over the 2024 comparable figure.

On the other hand, earnings estimates for RGTI remained unchanged at a loss of 5 cents per share for 2025 over the past 90 days. This implies an improvement of 86.1% over the 2024 comparable figure.

RGTI: A Sure Shot Pick at This Moment

Given the current situation, RGTI, a Zacks Rank #2 (Buy) stock, emerges as the stronger bet compared to IONQ. Backed by a fortified balance sheet, a chiplet-based architecture gaining traction through Microsoft Azure integration and steady government contracts, Rigetti is better positioned to convert R&D into near-term milestones. While IonQ, a Zacks Rank #3 (Hold) stock, has partnerships with hyperscalers like NVIDIA and government ecosystems that remain impressive, Rigetti’s strong strategic execution and earnings trajectory, along with alignment with Microsoft’s cloud-first quantum vision, make it the better pick for investors right now. You can see the complete list of today’s Zacks Rank #1 (Strong Buy) stocks here.

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This article originally published on Zacks Investment Research (zacks.com).

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