Let each complete draw ask whether the stream still looks like itself.

The newest score is ranked among all scores in that prefix. Random tie-breaking turns the rank into a conformal p-value $p_t$. Under exchangeability these p-values are uniform, without specifying the draw distribution.

For a fixed $0<\epsilon<1$, $\epsilon p_t^{\epsilon-1}$ is a betting factor. Products of those factors form a test martingale. The watch averages three predeclared martingales, so Ville's inequality makes a 20× crossing an anytime-valid 5% alarm.