KILLED · unstable sign
Hypothesis
BTC trades inversely to the US dollar index; using DXY moves as a directional overlay for BTC adds edge.
Math — rolling correlation
$$ \rho_t = \frac{\mathrm{Cov}(r^{BTC},r^{DXY})}{\sigma_{BTC}\,\sigma_{DXY}} $$
Method
Rolling 30/90-day BTC–DXY correlation; trade BTC on DXY signal when correlation is strongly negative.
Results
| Rolling correlation | swings −0.6 ↔ +0.4 |
| Sign stability | none |
| Overlay edge | none |
The "inverse correlation" is a part-time relationship — it is strongly negative in some regimes and positive in others, so an overlay built on it is right exactly as often as it is wrong. No stable, tradeable structure.
Macro correlations in crypto are regime-conditional and flip without warning. A relationship that is sometimes −0.6 and sometimes +0.4 is not a relationship you can trade.