QUBT vs RGTI: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of August 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. QUBT and RGTI share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined QUBT and RGTI exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

Quantum Computing Inc. (Nasdaq: QUBT), which operates as QCi, is an integrated photonics and quantum optics company. It designs photonic quantum machines, including its entropy quantum computer (the Dirac, marketed for binary and integer optimization problems), and develops thin-film lithium niobate (TFLN) chips for optical devices such as electro-optical modulators and frequency-conversion components. It intends to make money three ways: selling quantum machines to commercial and government customers, running a TFLN photonic-chip foundry for itself and outside customers, and providing semiconductor and packaging services. In June 2026 it completed the acquisition of NHanced Semiconductors for roughly $73 million in cash and stock to add fabrication, advanced-packaging, and engineering capacity.

Full QUBT guide

Rigetti Computing (RGTI) is a quantum computing company that designs and builds superconducting quantum processors and the full-stack systems and software around them. It operates an integrated approach: it fabricates its own quantum chips in an in-house foundry, builds multi-qubit quantum processing units, and offers access to its machines through Quantum Cloud Services and partner cloud platforms. Rigetti's strategy centers on improving qubit count, gate fidelity, and system reliability over successive processor generations, working toward machines that can eventually deliver advantages over classical computers for specific problems. Customers and partners include government, research, and enterprise organizations exploring quantum algorithms. The company is still in an early, pre-commercial-scale phase: revenue is small and inconsistent, and it operates at a loss while investing in hardware research and fabrication. Founded in 2013 and headquartered in Berkeley, California, Rigetti went public via a SPAC merger in 2022 and remains a long-horizon, speculative bet on whether superconducting quantum computing reaches practical, fault-tolerant utility.

Full RGTI guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• QUBT drivers: Photonics-first quantum approach; Foundry and vertical integration.
• RGTI drivers: Full-stack and in-house fabrication; Cloud access and partnerships.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: The bear case is that valuation is disconnected from fundamentals: trailing revenue is only a few million dollars against a market value near $2 billion, implying a price-to-sales ratio in the hundreds. For RGTI, rigetti is early-stage with small, inconsistent revenue and persistent operating losses, so it depends on its cash and periodic capital raises that can dilute shareholders heavily.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick QUBT if you believe its drivers more; RGTI if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the QUBT and RGTI guides.

QUBT. Valuation here is speculative, not fundamental. With only a few million dollars of trailing revenue against a roughly $2 billion market value, the implied price-to-sales ratio runs into the hundreds, and there are no positive earnings to anchor a P/E. The price reflects expectations for a still-pre-commercial technology, so figures can shift quickly and should be treated as a snapshot.

RGTI. Rigetti cannot be valued on earnings; revenue is small and inconsistent and the company loses money. The market prices it on the option value of quantum computing reaching practical utility years out, so the stock is extremely volatile and moves on sector sentiment, milestone news, and capital raises. Figures are approximate and change frequently; verify current revenue, cash, burn rate, and share count, which dilution can move materially.

Headline figures (approximate, 2026-06-26): QUBT shows share price ~$9.18, market cap ~$2.07 billion, revenue (ttm) ~$4.3 million (minimal), q1 2026 revenue ~$3.7 million (up from ~$39 thousand a year earlier); RGTI shows revenue (ttm) ~tens of millions, small and lumpy (verify), profitability Unprofitable; ongoing operating losses, cash burn ~tens of millions per year (verify latest), cash position Bolstered by equity raises; varies (verify current).

QUBT and RGTI are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined QUBT and RGTI exposure against your real portfolio. It is not an investment adviser.