What if the retail-media advertising bubble bursts?
A retail-media CPM crash punctures the highest-incremental-margin growth engine at Amazon/Walmart/Instacart — a real but second-order ad-segment hit, not a whole-company event, so the tape is mild risk-off. Rhymes with the 2022 digital-ad recession when over-built ad inventory met budget cuts and CPMs fell. Forward angle: retail media is now ~$50bn and propping retailer margins, so a crater pressures Walmart/Amazon operating-margin guidance more than headline revenue.
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. Overbuilt retail-media networks see CPMs crater as brands pull budgets, hitting Amazon, Walmart, Instacart ads. The trigger decomposes into signed root‑shocks — Risk appetite ▼ — which propagate through our causal graph to the markets below.