What if the best-funded fusion startup collapses?
A flagship fusion failure chills frontier-energy/AI capex sentiment; the tradable leg is semis lower with NVDA the bellwether and Micron/Broadcom the high-beta sleeve. Closest rhyme is the Jan-2025 DeepSeek selloff, which knocked the AI-capex complex on a demand-assumption re-rate. Skeptical: fusion is not in any 2026 power balance, so spillover is pure risk-appetite; the dip is shallow and likely bought unless it coincides with a broader capex-air-pocket.
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 1–3 years 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. The best-funded fusion venture folds after a failed scale-up, chilling investment across the entire sector. The trigger decomposes into signed root‑shocks — AI capex ▼ · Risk appetite ▼ — which propagate through our causal graph to the markets below.