What if the US taxes billionaires' unrealised capital gains?
A US mark-to-market tax on billionaire unrealized gains is a concentrated-equity-supply trade: forced liquidation of founder stakes pressures mega-cap growth (NVDA, TSLA, META) and derates long-duration names on a higher effective tax wedge. No direct analogue; nearest rhyme is the late-2021 growth-stock derating on rate fears and tax-loss/founder-selling dynamics. The forward risk: telegraphed selling invites front-running, so the air-pocket comes before enactment, not after.
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. Congress enacts mark-to-market tax on billionaire unrealized gains, forcing equity liquidation and growth-stock derating. The trigger decomposes into signed root‑shocks — Financial conditions ▲ · Risk appetite ▼ — which propagate through our causal graph to the markets below.