When financial analysts start comparing a sector to the dot-com bubble, prudent investors take notice. And right now, one corner of the technology market is drawing those comparisons with alarming frequency: pure-play quantum computing stocks.

Over the past year, shares of IonQ, Rigetti Computing, and D-Wave Quantum have each skyrocketed by more than 1,000%, turning obscure technology startups into the darlings of retail investors and AI enthusiasts alike. But beneath the extraordinary gains lies a troubling reality: virtually none of these companies have achieved meaningful commercial success, and their valuations have reached levels that history suggests are unsustainable.

The Valuation Problem

Consider Rigetti Computing, which trades at a price-to-sales ratio of roughly 1,025. For context, Palantir—widely considered the most expensive stock in the S&P 500—trades at approximately 120 times sales. Rigetti is literally ten times more expensive than Wall Street's most richly valued large-cap stock.

The other quantum pure-plays aren't much cheaper. IonQ trades at several hundred times revenue, and D-Wave Quantum carries a similarly stratospheric multiple. These valuations assume commercial success on a massive scale—success that remains theoretical at best.

Historical precedent offers a sobering warning. Before the dot-com bubble burst in March 2000, market leaders like Microsoft, Amazon, and Cisco Systems peaked at price-to-sales ratios above 30, occasionally exceeding 40. What followed was the most punishing market correction in a generation. Today's quantum computing valuations dwarf those figures by orders of magnitude.

Where's the Technology?

The fundamental problem facing quantum computing stocks is simple: the technology isn't ready for primetime. No company has yet constructed a large-scale, fault-tolerant quantum computer—a system that can correct errors in real time and possesses enough qubits to perform useful commercial computations.

Qubits, the fundamental units of quantum information, are notoriously fragile. They easily lose their quantum states when exposed to environmental noise, leading to high error rates that limit practical applications. Scientists estimate that useful quantum computing for complex problems like drug discovery or financial modeling may still be 5-10 years away.

A critical analysis reveals a striking fact: none of the quantum computing pure-plays achieved meaningful technological breakthroughs in 2025 or gained significant customer traction at the enterprise level. The stock gains were driven almost entirely by speculation and the general enthusiasm for AI-adjacent technologies.

Insider Selling Raises Red Flags

Perhaps most concerning is the behavior of company insiders. Several executives at D-Wave—including its CEO, CFO, and board members—have been selling shares in recent months. Similar insider selling has been observed at Rigetti, where the CEO has reduced his stake.

When the people with the most intimate knowledge of a company's prospects are liquidating their holdings, it raises questions about whether the current trajectory is sustainable. While insider selling can occur for various personal reasons, the pattern across multiple quantum computing companies is difficult to ignore.

The Big Tech Wild Card

Adding to the competitive pressure, technology giants are making significant strides in quantum computing. Alphabet debuted its quantum processing unit, Willow, in December 2024, running algorithms faster than the world's quickest supercomputers. Microsoft unveiled its own QPU, Majorana 1, in February 2025.

These developments present a double-edged sword for pure-play quantum stocks. On one hand, they validate that quantum computing is a real and advancing technology. On the other, they raise the question of why investors should bet on small, unprofitable companies when giants with vast resources are making comparable or superior progress.

The Bull Case—Such As It Is

Defenders of quantum computing stocks point to the long-term potential of the technology. If quantum computing eventually delivers on its promise—solving problems that are impossible for classical computers—the first-mover advantage could be enormous.

There's also precedent for patience. Many dot-com era companies that seemed hopelessly overvalued in 2000 went on to deliver life-changing returns over the following two decades. Amazon, which fell 95% from its 1999 peak to 2001, became one of history's greatest investments for those who held on.

The challenge, of course, is distinguishing which quantum computing companies—if any—will emerge as the Amazons rather than the Pets.coms of this cycle.

What 2026 Could Bring

Several factors could trigger a correction in quantum computing stocks this year:

  • Earnings Disappointments: As companies report quarterly results, the gap between valuations and fundamentals may become too obvious to ignore.
  • Interest Rate Sensitivity: Speculative stocks typically suffer when interest rates remain elevated, making future earnings less valuable in present-day terms.
  • Rotation to Profitable Tech: As investors seek companies with actual AI revenue, capital may flow out of speculative plays and into established winners.
  • Competitive Announcements: Major breakthroughs by Big Tech could highlight the disadvantages facing smaller pure-plays.

Investment Takeaways

For most investors, pure-play quantum computing stocks are best avoided or limited to true risk capital—money you can afford to lose entirely. The potential upside is enormous if the technology matures and these companies become leaders, but the valuation risk is equally enormous if commercial viability remains elusive.

Those interested in quantum computing exposure might consider a more diversified approach through companies like Alphabet, Microsoft, or IBM, which are investing in quantum technology but don't depend on it for their valuation.

The Bottom Line

The quantum computing bubble represents one of the most extreme examples of speculative excess in today's markets. While the underlying technology may eventually transform computing, the current valuations of pure-play stocks assume a level of commercial success that has no basis in current reality.

History suggests that when stocks trade at 1,000 times sales with no clear path to profitability, a correction is not a matter of if, but when. For investors in IonQ, Rigetti, and D-Wave, 2026 could be the year that bill comes due.