The criticality gear's prediction, sealed on fresh data
This is the load-bearing test: the whole criticality account turns on the claim that the effective number of independent blocks collapses across an onset. The honest story has a twist that took six runs to find, and it is a lesson in not testing the wrong quantity.
Dynamic Neff collapse — community-specificity
SEALED PASSThe theory's real claim is specificity: before an endogenous cascade, the existing community's frozen block partition collapses harder than a random reshuffle of the same people. We pre-registered that as the primary endpoint, with a frozen binomial rule, on a fresh roster of 12 r/wallstreetbets cascades disjoint from every prior run (COVID crash, Archegos, Coinbase, the NVDA earnings prints, Credit-Suisse, the 2024 election, and more). It passed cleanly.
validation/neff_v4/). Left: each cascade's canonical-Neff collapse against its own block-label-shuffle 90th percentile (dots); green bars fire, red do not. Right: the observed collapse sits at the very top of its own 300-shuffle distribution for most cascades. The three non-firing cascades are the mechanical / exogenous events (a direct listing, a single Fed rate decision, a stock split) — exactly where a frozen-block Neff should be silent.§ Why this is an honest pass, not a manufactured one. We did not relax the magnitude threshold an earlier run failed (that verdict stands, see below). We tested a different, theory-correct endpoint on fresh data. The September-2024 stimulus case clinches the logic: its raw collapse is only 0.065 — any magnitude bar would discard it — yet it beats every one of its 300 shuffles, because the signal lives in the community structure, not the magnitude.
The twist: why magnitude was the wrong yardstick
The raw-magnitude reading — non-discriminating
REPORTED, NOT GATINGTwo earlier sealed runs tested whether the collapse magnitude exceeds a threshold derived from genuinely-quiet windows. They failed, and the failure is informative: it is why we switched to specificity.
validation/neff_v3/). The decisive discovery was in the null itself: short high-volume onset windows compress Neff generically, so quiet windows already drop a median ~0.10. Magnitude therefore cannot tell an endogenous cascade from a busy-but-quiet week on a continuously high-volume forum. The specificity gate (does the real partition beat a shuffle?) discriminates where magnitude cannot.§ The reconciliation. The dynamic collapse is a real structural signal that lives in the block partition (the shuffle test sees it four times) but is not a magnitude excursion beyond a quiet baseline — which the near-decomposability premise never required. Both halves are reported. The full six-pass arc and the synthesis are in validation/NEFF_COLLAPSE_SYNTHESIS.md.
