Quantum computing is at an inflection point between genuine technical progress and unsustainable market valuations. Google's Willow chip demonstrated it could solve problems 13,000x faster than the world's most powerful supercomputers — a legitimate breakthrough in error correction that puts practical quantum computing closer to reality. IonQ's $1.8 billion acquisition of SkyWater in late January signals the industry is moving toward vertical integration and manufacturing scale.

But the market has gotten ahead of the science. Pure-play quantum stocks sold off 10-19% in January as investors confronted the reality that P/S ratios of 80-300x are historically untenable. IonQ trades at 86x P/S, Rigetti at 308x P/S, and smaller names like QUBT at 2,760x P/S. Even with triple-digit revenue growth, these valuations require everything to go right for a decade. The Motley Fool's assessment is blunt: "all the historical hallmarks for a quantum computing bubble are firmly in place."

The bull case rests on a $1 trillion total addressable market by 2035 (Quantum Insider) and $850 billion in global economic value by 2040 (BCG). The question is whether today's pure-plays capture that value, or whether the Mag-7 companies building quantum internally (Google, IBM, Microsoft) dominate while most startups go bankrupt before commercialization.