Resolves YES if LK-99 is shown, in scientific publications of sufficient quality to produce a consensus among physicists, to be more diamangetic than any known non-superconducting material at room temperature and pressure.

The most diamagnetic material currently known is pyrolytic graphite, with a magnetic susceptibility χ ≈ −4.5×10^−4 in one plane.

This market will resolve YES either:

• If LK-99 is superconducting at room temperature and pressure, in which case it would be extremely diamangetic indeed, or

• If LK-99 is not superconducting at room temperature and pressure, but has a negative and larger (i.e. more negative) magnetic susceptibility than that of pyrolytic graphite.

Resolves NO at the end of 2024 if no such evidence is forthcoming. I reserve the right to extend the market close date if at the end of 2024, there is new evidence under active consideration.

Update: I'll follow @QuantumObserver's criteria for whether impurities/alternative formulations count as LK-99 for the purposes of this market:

Materials Impurities:

This question is specifically about LK-99. In the absence of overwhelming expert consensus (see below about resolution caveats), adding materials not in the original synthesis or characterization (replacing Cu with Au, Ag, etc) will not count toward a YES resolution. 

Removing impurities (like CuS) is OK.

Increasing impurities that were also present in LK-99 original XRD is OK, up to a point. I think I would be more accepting of this is it’s convincingly shown that the impurities are important to the superconductivity of LK-99. 

Synthesis of LK-99 by other means is totally fine, as long as the material characterization satisfies the criteria above.