What if a seven-block reorg reverses finalized Ethereum transactions?
A seven-block reorg reversing finalized Ethereum transactions shatters the settlement-finality assumption every exchange relies on — the deepest tail here, ETH -8.3% with VIX ticking up as 'finality' itself is questioned. No clean modern analogue; the nearest mental model is a blockchain double-spend/deep-reorg combined with the 2022 contagion mechanics. If finality can reverse, exchanges must lengthen confirmation requirements, structurally raising settlement friction and re-rating ETH's monetary-premium lower until the bug is provably fixed.
Every number ships with its receipt — the odds, the range, the precedents, and a public grade at Reality Check. The statistical machinery that produces it is proprietary.
The butterfly cascade
How this trigger trickles across markets, left → right — the root shock, its first‑order moves, then the ripple effects. Drag any node; tap a market for its real price history.
Resolution timeline — how this probability is moving
Our model's odds (electric blue) over time vs the market's (Polymarket, amber), from the past toward the Tail risk horizon. Each dot is a real macro event that nudged the probability — green pushed it up, red pushed it down. Tap a dot for the source. Loading the probability audit trail…
What it would mean
If this plays out, it is a risk-off shock. A consensus bug triggers a seven-block Ethereum reorg, reversing finalized transactions and shattering exchange settlement assumptions. The trigger decomposes into signed root‑shocks — Crypto confidence ▼ · Risk appetite ▼ — which propagate through our causal graph to the markets below.