What if an HBM4 yield wall leaves SK Hynix the sole supplier?
An HBM4 yield wall leaving SK Hynix the sole volume supplier rations Rubin-class parts and spikes memory prices — a supply shock that pressures TSMC on output while concentrating pricing power in the one supplier. Echoes the 2017-18 DRAM shortage that handed memory makers record margins. Forward angle: roots correctly flag semiconductor_risk high and ai_capex positive — demand is fine; the asymmetry is single-source supplier concentration (SK Hynix the winner, Micron/Samsung the laggards).
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 mixed shock. HBM4's stacking yield wall leaves SK Hynix the only volume supplier, rationing Rubin-class accelerators and spiking memory prices. The trigger decomposes into signed root‑shocks — AI capex ▲ · Semiconductor supply risk ▲ — which propagate through our causal graph to the markets below.