This market is about whether quantum computing will fail to meaninfully manifest practical applications due to the following two failures, specifically:

• Large quantum speedups, i.e. exponential speedups in algorithm, fails to be delivered apart from specific, niche problems (e.g. integer factorisation). In particular, general quantum optimization algorithms, accelerated retrieval, or similar general algorithm, will end up admitting only polynomial speed-up, and therefore not be competitive with classical computing for real-life problem sizes.

• Fault tolerant quantum computing fails to materialize and theshold theorems are proved too optimistic. Noise correlation in real life quantum computers, combined with faillible gates means quantum error correction code are impractical.

The first metaphorical tower has already been severely hit (see here for a celebrated review), though new development are not formally ruled out. The second is speculative, and generally considered still intact.

This market therefore resolves Yes, if, on Oct. 17 2027, the consensus in the field is that quantum computing has failed/will fail to deliver practical use cases due to both of these failures.

The market resolves Yes, possibly before 2027, if formal proof of limitation 1 and 2 are shown to hold. This would be a true "quantum impossibility" tour de force, so don't count on it.

This market resolves No, possibly before 2027, in the event that working, general purpose quantum error correction code, for a practically useful number of qbits (definitely not just 5 or so) are demonstrated in real hardware.

This market resolves No, if quantum computing turns out impractical for reason unrelated to both of these, or only one of those is true, according to consensus on Oct. 17 2027 or before.

This market resolves No, if quantum computing is still consered broadly applicable in practice (whether because it is broadly applied at that date, or it is the consensus that only non-fundamental obstacles remain for application, and that the two failures described above have been overcome), according to consensus on Oct. 17 2027.

The consensus will be established by reading peer-reviewed review article on the question published near the close date, and/or blog post made by reputable persons in the quantum computing spheres if this is an outlook-based resolution like the last paragraph. The basis of resolution will be provided for verification.

In case of ambiguity, I reserve the right to close temporarily this market, discuss in the comments, and possibly resolve N/A if doubts remains. I welcome comments and suggestion on resolution criteria if they are provided well in advance of the resolving event.