What if AI mega-caps derate 25-30% as stretched valuations unwind?
The S&P 500 forward P/E unwinds from its ~96th-percentile reading as AI mega-caps derate 25–30%, the dot-com-style correction the IMF GFSR Oct-2025 flagged on stretched valuations.
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 6–18 months 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 S&P 500 forward P/E unwinds from its ~96th-percentile reading as AI mega-caps derate 25–30%, the dot-com-style correction the IMF GFSR Oct-2025 flagged on stretched valuations. The trigger decomposes into signed root‑shocks — Volatility (VIX) ▲ · AI capex ▼ · Recession signal ▲ · Risk appetite ▼ — which propagate through our causal graph to the markets below.