IonQ vs. Rigetti Computing: Which Quantum Stock Wins?

IonQ (NYSE: IONQ) and Rigetti Computing (NASDAQ: RGTI) are two prominent pure-play quantum computing stocks. However, IonQ has clearly taken a lead in technical metrics and commercial momentum, making it a smarter pick for long-term investors.

Here's more to this story.

IonQ's growth drivers

IonQ's third-quarter (ending Sept. 30, 2025) revenues soared 222% year over year to $39.9 million, coming in 37% above the upper end of the guidance. Management raised the company's fiscal 2025 revenues outlook to $106 million to $110 million, up from the previous estimate of $82 million to $100 million.

IonQ has already achieved 99.99% two-qubit fidelity (the accuracy of two quantum bits working together without making mistakes). The company has introduced the Tempo system with an algorithmic qubit score of 64 (working with 64 reliable and high-quality qubits) and claims its computational space to be 260 million times larger than its commercialized Forte system and 36 quadrillion times that of its closest competitors' quantum machines. Tempo has already been running in the third quarter, three months ahead of schedule, and should ship in 2026.

With $3.5 billion in cash and no debt, the company appears to be a commercially strong and well-capitalized stock now.

Rigetti Computing's growth drivers

In the third quarter (ending Sept. 30, 2025), Rigetti Computing's revenues were down 18% year over year to $1.95 million, partly due to pending reauthorization of the sales under the National Quantum Initiative in the U.S. Congress. Gross margin dropped by 30 percentage points year over year to 21%, while operating loss expanded from $17.3 million to $20.5 million in the same time frame.

Rigetti is working on an impressive technology roadmap, aiming for a 100-plus qubit system at 99.5% fidelity by the end of 2025, a 150-plus qubit system at 99.7% fidelity in 2026, and a 1000-plus qubit system at 99.8% fidelity in 2027. However, these technology goals have not yet translated to meaningful commercial traction.
With nearly $600 million in cash, significantly lower than IonQ's cash balance, Rigetti appears to be a riskier bet for retail investors, despite its promising technology pipeline.

Manali Pradhan, CFA has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends IonQ. The Motley Fool has a disclosure policy.